Ter Neuzen v Korn: HIV, Artificial Insemination, and the Rule That Common Practice Is Not Always a Defence

Canadian medical malpractice law rests on a principle that protects physicians who act in accordance with the established practices of their profession. That principle is real, well-founded, and essential to the fair assessment of clinical conduct. But it has a limit. Ter Neuzen v Korn is the Supreme Court of Canada decision that defines that limit, establishing precisely when common professional practice is a complete answer to an allegation of negligence, and precisely when it is not.

The case arose from one of the most medically and legally freighted situations of the 1980s: a woman who contracted HIV through artificial insemination at a time when the medical world was only beginning to understand a virus that would define a global epidemic. The physician who performed the procedure had followed every practice that was standard in his field. The jury that heard the case found him negligent anyway. The question that wound from a Victoria courtroom to the Supreme Court of Canada was whether that finding was legally permissible, and if so, under what conditions.

The answer Justice Sopinka gave for a six-member majority reshaped how Canadian courts approach the standard of care. The technical versus non-technical distinction, the limits of expert evidence, the procedural allocation of standard-of-care questions between judge and jury, the position of biological substances in warranty law, and the governance of the non-pecuniary damages cap in jury trials: Ter Neuzen v Korn addressed all of these, and every one of its holdings continues to govern Canadian malpractice litigation today.

The World in January 1985: What Was and Was Not Known About HIV

To understand Ter Neuzen v Korn, one must understand the state of medical knowledge about HIV in January 1985, not the knowledge of 1995 when the SCC decided it, or 2025 when this article is read, but the knowledge of the months immediately preceding the infection that gave rise to the claim. The SCC was explicit about this requirement: a physician’s conduct must be judged in the light of the knowledge that ought reasonably to have been possessed at the time of the alleged act of negligence, not in the light of what became known afterward.

AIDS was first reported in the medical literature in June 1981, initially as an illness affecting homosexual men and known as Gay-Related Immunodeficiency (GRID). By early 1983, the first report appeared of HIV infection in female sex partners of AIDS patients, establishing heterosexual transmission as a possibility. The virus was isolated in May 1983. Its link to blood transfusions was identified in December 1983. In 1984, the development of the ELISA antibody test in the United States represented a remarkable scientific achievement, but the test was not available for clinical use in Canada until November 1985. No test for HIV existed in Canada in January 1985.

In mid-1984, four babies in Australia acquired AIDS through blood transfusions. This led to a multi-disciplinary government task force and, in late November or early December 1984, to a ministerial decree closing all AI clinics in Australia pending the availability of the ELISA test. This decision was controversial in the Australian medical community (there had been no documented cases of HIV transmission through AI at that point) and it was not widely publicized in North America. The respondent, like virtually all North American practitioners, did not know about it.

The first documented case in the world of HIV transmission through AI was published in the lay media in July 1985 and in a medical journal (an article in the British journal Lancet by Dr. Stewart and colleagues, reporting that four Australian women had been infected through AI from a single bisexual donor) in September 1985. The critical date of the appellant’s infection was January 21, 1985: five months before the first public report and eight months before the first scientific publication.

The knowledge gap between the international cutting edge of HIV research and what Canadian practitioners could reasonably be expected to know was significant and genuinely contested. No obstetric literature had mentioned AI as a route of HIV transmission. No professional society had issued guidelines about HIV and AI. No Canadian AI practitioner had changed their practice by January 21, 1985 because of the HIV risk. The state of knowledge among Canadian obstetricians and gynaecologists practising AI in January 1985 was that HIV was a disease of high-risk groups, that transmission required bodily fluids, that the atraumatic nature of AI was thought to distinguish it from sexual intercourse as a potential transmission route, and that there were no documented AI-HIV cases.

The Parties and the AI Program

Kobe ter Neuzen

The appellant, Kobe ter Neuzen, was a psychiatric nurse. She began participating in the respondent’s artificial insemination program in 1981 when she was in her mid-thirties, seeking to become pregnant. From 1981 to January 1985 she underwent approximately 33 to 35 AI procedures, paying the respondent a fee of approximately $60 per procedure, most of which the respondent paid to the semen donor, retaining a small administration fee. The balance of the cost was covered by her medical plan. The last procedure she underwent was January 21, 1985, which the respondent admitted was the procedure through which she became infected with HIV.

Dr. Gerald Korn

The respondent, Dr. Gerald Korn, was an obstetrician and gynaecologist who had been certified as a specialist in that field since 1958. He had practised AI since 1974, making him one of the most experienced AI practitioners in British Columbia; in fact, by 1985 he was performing almost all AI procedures in the province. He had over 200 donors and had treated more than 1,600 patients for AI, resulting in over 500 births. He had been Acting Chief of Obstetrics at the University Hospital and held positions at the University of British Columbia.

Dr. Korn’s AI practice involved careful personal interviewing of all prospective donors. He obtained complete medical histories, assessed sexual activity levels, and specifically asked about homosexuality, not because of HIV, but because he recognized homosexual men as a higher risk group for conventional sexually transmitted diseases generally. He conducted general physical examinations, took semen samples and cultures, and tested for gonorrhoea, syphilis, Rh blood factor, and other bacterial conditions. He used only fresh semen prior to January 1985. He had 28 active donors at the relevant time.

When the respondent learned in July 1985 that an AI program in Australia had produced HIV-positive patients, he immediately discontinued his AI program and recommended testing for all his donors and recipients. The donor whose semen had been used in the appellant’s January 21, 1985 procedure tested HIV positive. When the respondent then asked that donor again about his sexual orientation, the donor disclosed he was bisexual, a fact he had concealed during his initial interview. Only one other patient of Dr. Korn’s tested HIV positive. The Lancet article documenting the Australian cases appeared in September 1985.

The Litigation: A Three-Court Journey

Stage One — The Trial (November 1991, Victoria)

Kobe ter Neuzen brought an action against Dr. Korn for negligence. The trial before Justice Hutchison with a jury ran for approximately three weeks in November 1991 in Victoria, British Columbia. It was, as Justice Hutchison later noted in his costs ruling, the first Canadian medical malpractice suit alleging an HIV-positive diagnosis resulting from negligence. Before trial, the respondent admitted causation: that the appellant became HIV positive as a result of the AI procedure on January 21, 1985. The liability questions for the jury therefore concerned what the respondent should have known and done, not whether he was the source of the infection.

The expert evidence ranged widely. Dr. Stewart, an Australian immunologist with experience treating HIV and AIDS patients, testified for the appellant that by January 1985 the transmission of HIV by AI should have been suspected and patients should have been warned. Dr. Mascola, a medical epidemiologist who was the first person in the world to express concern about HIV transmission through AI in her October 1983 letter to the New England Journal of Medicine, testified that she would not have expected an obstetrician to read the journals where her concern was published, and that no obstetric literature mentioned AI as a mode of HIV transmission before 1986. Both Dr. Stewart and Dr. Mascola ultimately directed their criticisms at the Canadian public health system rather than at the respondent personally.

Dr. Wass, a clinical hematologist who had cared for AIDS patients since 1982 and served as President of AIDS Vancouver, testified for the defence that it never occurred to her before January 1985 that HIV could be transmitted through AI. Dr. Scott, an Edmonton AI specialist who had directed over 3,000 AI pregnancies, testified that the respondent’s practice was in keeping with general practices across Canada and that he himself did not know HIV could be transmitted through AI until mid-1985.

The trial judge instructed the jury on two alternative bases for finding negligence: first, that the respondent had failed to conform to the standard medical practice applicable at the time; second, that the approved or standard practice itself was negligent. The jury found in favour of the appellant and assessed damages at $883,800, including $460,000 for non-pecuniary damages. The $460,000 non-pecuniary award was nearly double the inflation-adjusted rough upper limit of approximately $240,000 applicable at the time.

After the jury verdict, Justice Hutchison awarded the appellant Scale 4 costs, finding the case was one of “more than ordinary difficulty or importance” given its novelty and complexity, but not Scale 5 because the causation issue had been conceded by the respondent before trial.

Stage Two — The British Columbia Court of Appeal (June 1993)

Dr. Korn appealed. The Court of Appeal, in reasons delivered by the court as a whole through McEachern CJA (Seaton and Proudfoot JJA), allowed the appeal and ordered a new trial.

The Court of Appeal divided the negligence claim into two aspects, a division that would be adopted and developed by the Supreme Court of Canada. The first aspect concerned the failure to be aware of the HIV-AI transmission risk and to warn patients or discontinue the AI program. The Court of Appeal concluded that on the evidence, it was not possible for a jury acting judicially to have found the respondent negligent on this ground: the state of medical knowledge in North America in January 1985 made it impossible for a reasonable practitioner to have known of this risk, and the trial judge should have instructed the jury to confine itself to the prevailing standard of practice on this aspect.

The second aspect concerned the screening and follow-up of donors. Here the Court of Appeal found the case was less clear: less technical scientific knowledge was required, and it was open to the jury to find that the screening procedures were deficient. The donor in question had been asked about his sexual orientation but not about bisexuality specifically. A follow-up interview might or might not have revealed his bisexuality.

Because the jury’s single yes/no answer on negligence made it impossible to determine whether they had found liability on the HIV-knowledge aspect (which should have been unavailable to them) or the screening aspect (which was available), the verdict could not stand. A new trial was ordered on the screening aspect and on damages. The Sale of Goods claim was dismissed. The non-pecuniary damages could not exceed the adjusted rough upper limit.

Stage Three — The Supreme Court of Canada (October 1995)

Ter Neuzen appealed to the Supreme Court of Canada. Four groups intervened: the HIV-T Group (Blood Transfused), the Canadian Association of Transfused Hepatitis C Survivors, the Canadian Hospital Association, and the Canadian Red Cross Society, reflecting the broad institutional stakes of the standard of care and warranty questions the case raised.

The panel of seven justices heard argument on February 2, 1995, and delivered judgment on October 19, 1995. Sopinka J. wrote the majority reasons for La Forest, Gonthier, Cory, McLachlin, and Iacobucci JJ. L’Heureux-Dubé J. concurred in dismissing the appeal but wrote separately, dissenting on one point about the trial judge’s instruction to the jury regarding the non-pecuniary damages cap. The appeal was dismissed. The Court of Appeal’s order for a new trial was affirmed.

The SCC’s Analysis: Five Distinct Holdings

First Holding: The Technical versus Non-Technical Distinction in Standard of Care

The most significant legal contribution of Ter Neuzen v Korn is the framework Sopinka J. articulated for determining when common professional practice is sufficient to discharge the standard of care, and when it is not.

Sopinka J. began from established ground. Physicians are required to conduct their practice in accordance with the conduct of a prudent and diligent doctor in the same circumstances. A specialist must exercise the degree of skill of an average specialist in their field. The conduct of physicians must be judged in the light of the knowledge that ought reasonably to have been possessed at the time of the alleged act of negligence. These propositions, derived from Crits v Sylvester (1956 CanLII 34 ON CA; 1956 CanLII 29 SCC), Wilson v Swanson (1956 CanLII 1 SCC), and Lapointe v Hôpital Le Gardeur ([1992] 1 SCR 351), were not in dispute.

What was in dispute was the question Sopinka J. framed this way: where a physician conforms to the standard practice of their profession, under what circumstances can a court or jury nonetheless find that practice itself to be negligent? Drawing on Professor Fleming’s Law of Torts, on Anderson v Chasney (1949 CanLII 236 MB CA; affirmed 1950 CanLII 336 SCC), and on L’Heureux-Dubé J.’s analysis in Roberge v Bolduc ([1991] 1 SCR 374), Sopinka J. stated the governing principle as follows:

“As a general rule, where a procedure involves difficult or uncertain questions of medical treatment or complex, scientific or highly technical matters that are beyond the ordinary experience and understanding of a judge or jury, it will not be open to find a standard medical practice negligent. On the other hand, as an exception to the general rule, if a standard practice fails to adopt obvious and reasonable precautions which are readily apparent to the ordinary finder of fact, then it is no excuse for a practitioner to claim that he or she was merely conforming to such a negligent common practice.”

The principle has two components, and both are essential to understanding its operation.

The General Rule: Deference to Technical Standard Practice

Where a common and accepted course of conduct is adopted based on the specialized and technical expertise of professionals, courts and juries generally cannot substitute their lay judgment for that of the profession. Medicine involves decisions that require clinical training, diagnostic experience, and scientific knowledge that lay persons simply do not possess. Where a medical practice has been established by qualified practitioners working within their field of expertise, the courts are in no position to second-guess that professional judgment without the assistance of expert evidence, and where expert evidence confirms that the practice conforms to professional standards, that evidence will ordinarily be followed.

Conformity with general professional practice, Sopinka J. acknowledged, carries significant evidentiary weight. It tends to show what others in the same field considered adequate, that the defendant could not have learnt how to avoid the harm by the example of others, and that the impact of an adverse finding would be felt across the profession. Where the practice in question involves “difficult, uncertain, highly technical scientific questions requiring information not ordinarily expected of a practising” specialist, no jury is capable of deciding on its own what understanding a practitioner should bring to their practice. Such findings require expert evidence.

The Exception: Obvious Precautions Within Common Understanding

However, conformity with common practice is not an absolute defence. Where the alleged negligence concerns obvious and simple precautions that any reasonable person could recognize as necessary, without requiring any specialized clinical or diagnostic expertise to evaluate, a court or jury may find the practice negligent even if it was universal among practitioners. If a profession collectively fails to adopt measures that elementary common sense identifies as obviously necessary, that collective failure does not immunize individual practitioners.

The test, as Sopinka J. formulated it, is whether “the standard practice is fraught with obvious risks such that anyone is capable of finding it negligent, without the necessity of judging matters requiring diagnostic or clinical expertise.” The nature of the alleged negligence, not the professional category of the defendant, determines which side of the line the case falls on.

Crits v Sylvester as the Illustration of the Exception

To illustrate the exception, Sopinka J. reached directly back to the case that produced the governing medical standard of care formulation, Crits v Sylvester. That case, he explained, presented exactly the kind of non-technical negligence that falls within the exception: an anaesthesiologist who allowed explosive ether-oxygen vapour to accumulate near a patient’s head by failing to shut off an oxygen supply that should have been shut off. It required no specialized clinical knowledge to recognize that leaving explosive gas flowing in proximity to a child’s face, during a procedure generating static electricity, was an obvious risk. The question was one “which the ordinary man is competent to consider in arriving at a decision as to whether or not there was negligence.” Common practice did not protect Dr. Sylvester because the precaution at issue, shutting off the oxygen, was not a matter of clinical judgment. It was a matter of elementary common sense.

Crits v Sylvester and Ter Neuzen v Korn therefore form a complementary pair. The former established the standard of care formulation. The latter determined when compliance with that standard by reference to professional practice is assessed by expert evidence (technical cases, the general rule) and when it may be assessed by lay judgment alone (non-technical cases, the exception). For the full analysis of the standard of care formulation and how it was established, see the companion article on Crits v Sylvester in this series.

A Question of Law for the Trial Judge

Sopinka J. added a crucial procedural holding that is often overlooked: the question of whether a trier of fact can find that a standard practice is itself negligent is a question of law to be determined by the trial judge, irrespective of the mode of trial. It is not a question to leave to the jury without direction. If the case involves technical matters falling under the general rule, the trial judge must instruct the jury that once the standard practice is established by evidence, the only remaining question is whether the defendant conformed to it. If the case falls within the non-technical exception, the trial judge must instruct the jury that it is entitled to assess the adequacy of the practice based on common sense, without being bound by the expert consensus.

Sopinka J. also recommended that, to avoid the problem of inscrutable jury verdicts like the one in this case, questions to juries about negligence should require the jury to specify in what respects the defendant was negligent, allowing a court to assess whether the jury understood and applied the applicable legal framework.

Second Holding: The Two Aspects of the Negligence Claim — and Their Different Outcomes

Applying the framework to the facts, Sopinka J. confirmed the Court of Appeal’s division of the negligence claim into two aspects and agreed that each required a different analysis.

On the first aspect (the failure to be aware of the HIV-AI transmission risk and to warn patients or discontinue the program), Sopinka J. agreed with the Court of Appeal that no jury acting judicially could have found Dr. Korn negligent. The state of medical knowledge in January 1985 made it impossible for a reasonable practitioner to have known of this risk. The standard of care is assessed prospectively, against knowledge available at the time, and that knowledge did not include the HIV-AI link. Moreover, the question of what a practitioner should know about the state of HIV science in 1985 was precisely the kind of technical, uncertain, highly scientific question that was beyond ordinary jury competence. The trial judge’s instruction that the jury could find the standard practice itself negligent on this aspect was therefore incorrect. On this ground, the appellant’s claim simply fails: no new trial is warranted because no new evidence could produce a finding of negligence that would be supportable.

On the second aspect, the screening and follow-up of donors, the analysis was different. HIV is one of a number of sexually transmitted diseases. It was Dr. Korn’s duty to take reasonable steps to protect his patients against sexually transmitted diseases. A physician can be liable for damage caused by a failure to take reasonable STD precautions even if the specific disease that resulted was not foreseen, provided the class of injury, STD transmission, was foreseeable. The evidence of standard practice for donor screening was, in Sopinka J.’s characterization, “sketchy.” It was genuinely unclear whether a recognized standard of donor screening existed in Canada in January 1985.

Whether the jury should defer to a standard practice or set the standard themselves depended on the nature of the screening questions. The question of what screening protocols a prudent AI practitioner should have used to identify and exclude high-risk donors (such as whether to ask specifically about bisexuality as well as homosexuality, whether to re-interview donors periodically, whether to use a written questionnaire) was not the same kind of complex scientific question as the HIV-AI transmission risk. It was a question about reasonable precautionary conduct more accessible to common sense. The jury could assess what a prudent and diligent practitioner ought to have done, with or without a fully established standard practice to defer to. A new trial was necessary because the jury may have found negligence on this basis, but the misdirected instruction on the first aspect made it impossible to know.

Third Holding: The Sale of Goods Act Does Not Apply

As an alternative ground, the appellant had argued that the respondent breached an implied warranty under the British Columbia Sale of Goods Act that the semen would be of merchantable quality and fit for its purpose. The jury had answered “no” to the question of whether the contract was primarily for the sale of a good, and the Court of Appeal had upheld that answer. Sopinka J. agreed.

For the Sale of Goods Act to apply, a contract must primarily be for the purpose of selling goods. If the sale of a good is merely incidental to what is primarily a contract for services, the statute will not imply a warranty. The AI procedure was primarily a contract for medical professional services: the respondent’s expertise in donor selection, the AI procedure itself, and the medical knowledge and care that accompanied it. The provision of semen was a necessary component but was not the primary purpose for which the appellant engaged the respondent. She went to a gynaecologist for professional medical expertise, not to purchase semen. The jury’s characterization of the contract as primarily one for professional services was correct and supported by the evidence.

Fourth Holding: No Common Law Warranty for Biological Substances in Medical Contracts

The Sale of Goods Act dismissal did not end the warranty question, because a court may imply a warranty of fitness and merchantability in a contract for goods and services as a matter of common law, even where the statute does not apply. The appellant argued that such a warranty should be implied here: that the respondent had warranted the semen would not be contaminated with HIV.

Sopinka J. acknowledged the general common law principle, drawn from English cases including G. H. Myers and Co v Brent Cross Service Co [1934] 1 KB 46 and Young and Marten Ltd v McManus Childs Ltd [1969] 1 AC 454, and confirmed in Canadian courts, that where a contract for work and materials is performed, the materials are ordinarily warranted to be of good quality and reasonably fit for their purpose. But this warranty is not absolute and may be excluded where the circumstances of the contract are such as to exclude it.

In the medical context, different considerations apply. Drawing extensively on American authorities dealing with blood transfusion cases (particularly Perlmutter v Beth David Hospital (1954), Fisher v Sibley Memorial Hospital (1979), and St Luke’s Hospital v Schmaltz (1975)), Sopinka J. identified three reasons why implying a warranty of merchantable quality in the provision of biological substances in medical contracts would be inappropriate.

First, the rationale underlying commercial implied warranties, namely that a supplier can recover up the chain of production from the manufacturer, does not apply in the medical context. A physician who receives infected semen from a donor cannot sue the donor for breach of warranty. Biological substances are not manufactured goods, and the supplier has no recovery mechanism against a source of natural biological contamination.

Second, biological products such as blood and semen carry inherent risks. Unlike manufactured goods that ought to be removable from commerce if they cannot be made safe, biological substances essential to medical procedures cannot be held to a standard of defect-free perfection. A physician cannot control the safety of biological substances beyond exercising the reasonable care expected of a professional to ensure they are free from detectable harmful agents.

Third, the art of healing frequently calls for a balancing of risks and dangers. Imposing strict liability through warranty on a physician for biological products used in medical care would make physicians insurers of those substances, regardless of fault. This would be inconsistent with the general principle of Canadian medical malpractice law that physicians have obligations of means, not obligations of result.

The appropriate remedy in cases of this kind is confined to negligence. The warranty claim failed.

Fifth Holding: The Non-Pecuniary Damages Cap Applies and the Trial Judge’s Role

The jury’s non-pecuniary damages award of $460,000 was nearly double the inflation-adjusted rough upper limit of approximately $240,000 applicable at the time. The appellant argued that her situation, contracting a fatal illness through a routine medical procedure, with the certainty of eventually developing AIDS and dying prematurely, was so unique that the cap established in the 1978 Damages Trilogy should not apply.

Sopinka J. declined to recognize an exception. The functional approach to non-pecuniary damages means that awards are assessed based on what money can provide to alleviate the plaintiff’s suffering, not on the magnitude of the loss itself. The upper limit was imposed to prevent “extravagant claims” and to manage the social burden of damage awards, not because $240,000 precisely captures the worth of any particular plaintiff’s suffering. Every catastrophic injury case can be characterized as unique; that is the nature of catastrophic injury. The cap applies to all of them, not just to those that resemble the Andrews trilogy cases. As Sopinka J. stated: “There is no doubt that the appellant has suffered immensely as a result of this tragedy… However, with respect to non-pecuniary losses, I do not believe that the present case is any different than other tragedies.”

Sopinka J. then addressed the trial judge’s role when jury non-pecuniary awards might approach or exceed the upper limit. He held that a trial judge should instruct the jury on the upper limit if, after considering submissions of counsel, the damages by reason of the type of injury might very well be assessed in the range of or exceeding the upper limit. If the trial judge concludes the injuries will not likely produce an award approaching the limit, no instruction is required. Regardless of whether an instruction was given, if the jury’s award exceeds the limit, the trial judge must reduce it to conform with the cap adjusted for inflation, and need not wait for an appeal to do so.

In the present case, the trial judge had not given the instruction (neither counsel had requested one) and this was not an error on the facts. But the award of $460,000 far exceeded the adjusted limit, and the trial judge should have reduced it. A new trial on damages was ordered, and the trial judge at the new trial was directed to charge the jury on the upper limit given its likely relevance.

L’Heureux-Dubé J. agreed with the disposition but dissented on the instruction point. In her view, the jury should be left to determine non-pecuniary damages without instructions on the upper limit, subject only to the trial judge’s power to reduce an excessive award post-verdict. She argued that instructing the jury on the limit converts what is constitutionally a question of fact for the jury into a question of law for the judge, and noted the absence of any empirical evidence that the existing system produced systematically excessive jury awards requiring the modification Sopinka J. proposed.

What Ter Neuzen v Korn Established: Four Principles for Modern Malpractice Practice

Principle One: Common Practice Is Not Automatically a Defence — But Usually Is

Ter Neuzen v Korn confirmed that conformity with established professional practice generally exonerates a physician from negligence, but does not do so categorically. The case establishes both the rule and its precise exception. Practitioners and their legal advisers need to understand both, because cases that superficially resemble each other may fall on opposite sides of the technical/non-technical divide.

Most malpractice allegations involve matters of clinical judgment, diagnostic reasoning, treatment selection, or technical procedure, all of which fall squarely under the general rule. A radiologist who follows the accepted interpretive protocol for imaging studies is not negligent even if the diagnosis turns out to be wrong. A surgeon who follows the standard technique for a procedure is not negligent if a known complication occurs. An AI practitioner who screens donors in accordance with North American professional standards in 1985 is not negligent for failing to know what no one in North America yet knew.

But a healthcare provider who omits an elementary, obvious precaution that anyone would recognize as obviously necessary, who fails to do something so plain that no clinical expertise is required to see it should be done, cannot hide behind the fact that others in their field also omitted it.

Principle Two: The Standard-of-Practice Question Is Gatekept by the Trial Judge

The procedural holding in Ter Neuzen v Korn is as important as the substantive one. The question of whether a particular case falls under the general rule or the exception, whether the jury may or may not find a standard practice itself negligent, is a question of law for the trial judge. Trial judges must make this determination before instructing the jury, and their instructions must reflect it accurately.

The consequence of an incorrect instruction on this point, as this case illustrates dramatically, is a new trial. Juries given too much latitude to override standard professional practice may convict for conduct that was objectively defensible. Juries not given enough latitude may be prevented from finding negligence in matters of elementary common sense. The trial judge’s gatekeeping function is essential to the proper operation of the standard.

The related recommendation, that juries be asked to specify in what respects the defendant was negligent, not merely whether they found negligence, addresses the problem of inscrutable general verdicts that make appellate review impossible.

Principle Three: Biological Substances in Medical Contracts Are Governed by Negligence, Not Warranty

Ter Neuzen v Korn settled the question that had been debated in the United States for decades: whether the provision of biological substances in the course of medical treatment attracts implied warranty liability, either under sale of goods legislation or at common law. The answer in Canada is no. The appropriate cause of action is negligence. A physician who provides blood, semen, tissue, or other biological material in the course of rendering medical services does not warrant that the material will be free from contamination; they undertake to exercise the care, skill, and diligence of a reasonably competent practitioner.

This conclusion reflects both the structural realities of medical practice (physicians cannot recover from biological donors the way commercial suppliers can recover from manufacturers) and the inherent characteristics of biological substances that distinguish them from manufactured goods.

Principle Four: The Non-Pecuniary Cap Applies Even to Novel Injury Profiles

Every plaintiff who seeks non-pecuniary damages for a catastrophic injury can argue that their suffering is unique. Ter Neuzen v Korn confirms that uniqueness of the injury category does not lift the cap. The appellant’s situation, contracting a then-incurable fatal illness through a routine medical procedure, at a time when the disease itself was new and poorly understood, was as novel as injury profiles come. The cap applied nonetheless.

The ongoing significance for medical malpractice claims is that regardless of the type of injury, whether it involves a familiar physical disability or a less familiar condition like HIV infection, an acquired autoimmune disorder, or a rare iatrogenic complication, the plaintiff’s non-pecuniary damages will be assessed against the same inflation-adjusted ceiling. What varies is the total award, driven by the uncapped pecuniary components: future care, lost income, and out-of-pocket losses. For a full analysis of the 1978 Damages Trilogy cases that established the cap, see the companion article in this series.

Ter Neuzen v Korn in the Malpractice Litigation Landscape

Where the Technical/Non-Technical Line Is Drawn

The technical versus non-technical distinction from Ter Neuzen v Korn is regularly litigated in Canadian malpractice cases. Understanding where the line typically falls is essential for both plaintiffs and defendants assessing the viability and strategy of claims.

Technical matters, where the general rule of deference to standard practice applies, and where expert evidence is required to challenge that practice, include: clinical diagnosis and differential diagnosis; selection of treatment modality from recognized alternatives; specific surgical or procedural technique; pharmacological dosing and administration; interpretation of diagnostic imaging, laboratory results, or pathological specimens; and decisions about the timing and escalation of clinical intervention. These are areas where professional expertise is genuinely required to assess whether the course followed was appropriate.

Non-technical matters, where the exception may apply and the jury can assess adequacy without specialist expertise, include: failure to ask obvious questions that any prudent person would ask; failure to document; failure to communicate findings to the patient; obvious failure to monitor a known risk; failure to implement readily available safety measures against recognized dangers; and lapses in basic procedural safeguards (the sponge counting in Anderson v Chasney, the oxygen valve in Crits v Sylvester). These are areas where clinical expertise is not required to recognize the inadequacy, where it is within “the ordinary common sense” of a judge or jury to assess.

The Intersection with Informed Consent

Ter Neuzen v Korn intersects with the informed consent framework in a specific way: the duty to warn patients of material risks, which is governed by the Hopp v Lepp / Reibl v Hughes framework, is itself identified by Sopinka J. as one of the categories falling within the non-technical exception. A failure to disclose a known risk to a patient is not a matter requiring specialized diagnostic or clinical expertise to evaluate; it is a matter of basic communication. Professor Fleming’s observation, quoted by Sopinka J., notes that “omission to inform the patient of risks” falls among the matters on which “an ordinary person may presume to pass judgment sensibly.” This means that on disclosure questions, juries are generally permitted to assess whether adequate warning was given without being required to defer to evidence of prevailing professional disclosure norms.

For the full analysis of when and how the informed consent duty applies (the Hopp formulation and the Reibl modified objective causation test), see the companion article on Hopp v Lepp and Reibl v Hughes in this series.

The Prospective Assessment and Wilson v Swanson

Ter Neuzen v Korn reinforced the principle, originating in Wilson v Swanson and emphasized in Lapointe v Hôpital Le Gardeur, that the standard of care is assessed against the knowledge available at the time of the alleged negligence. Sopinka J. quoted Lord Denning’s formulation from Roe v Ministry of Health [1954]: “We must not look at the 1947 accident with 1954 spectacles,” adapted by the trial judge in this case to a 1985 problem that should not be assessed through 1991 spectacles.

For the full analysis of the error in judgment doctrine and prospective standard of care assessment, see the companion article on Wilson v Swanson in this series.

Conclusion: The Limits of Professional Deference

Kobe ter Neuzen contracted HIV through an artificial insemination procedure in January 1985, at a moment when medicine stood at the threshold of understanding an epidemic that would kill tens of millions of people. The physician who performed the procedure did everything his profession then expected of him. He used standard technique, followed standard screening protocols, and could not have known what no practitioner in North America yet knew. Five months later, the first documented case of HIV transmission through AI was published in a medical journal. The knowledge that could have changed the outcome, the knowledge that could have prompted a warning, or a cessation of the AI program, or a change in donor protocols, did not yet exist in a form that reached practitioners like Dr. Korn.

The Supreme Court of Canada’s response to this tragedy was careful, principled, and consequential. It distinguished between what a physician should be held accountable for in light of what was reasonably knowable at the time, and what the specific jury should have been permitted to decide without more. It separated the profound wrong done to the appellant from the question of whether the law could find the respondent legally responsible for a risk that the entire medical community had not yet recognized. And in doing so, it produced a framework that has governed the standard of care in every technical and non-technical malpractice case in Canada since 1995.

The technical versus non-technical distinction does not privilege the medical profession or immunize physicians from accountability. What it does is ensure that accountability is assessed fairly: against what could actually be known and done in the circumstances, with expert evidence where specialized knowledge is required and ordinary judgment where common sense suffices. A profession that collectively fails to observe obvious safety precautions is not immunized by the collective failure. A practitioner who genuinely could not have known what was not yet known is not held to knowledge they could not have had. Between these limits lies the standard of care in Canadian medical malpractice law.

Quick Reference: Ter Neuzen v Korn

The Three Decisions

• Trial costs: Neuzen v Korn, 1991 CanLII 1662 (BC SC) https://canlii.ca/t/1crbd | Hutchison J. | December 23, 1991 | Scale 4 costs awarded to plaintiff; the first Canadian medical malpractice suit alleging HIV diagnosis resulting from negligence
• Court of Appeal: Neuzen v Korn, 1993 CanLII 2881 (BC CA) https://canlii.ca/t/1dc3t | McEachern CJA, Seaton and Proudfoot JJA | June 21, 1993 | Appeal allowed; new trial on screening negligence and damages; jury verdict set aside
• Supreme Court of Canada: Ter Neuzen v Korn, 1995 CanLII 72 (SCC), [1995] 3 SCR 674 https://canlii.ca/t/1frhk | Sopinka J. (majority, 6); L’Heureux-Dubé J. (partial dissent on damages instruction) | October 19, 1995 | Appeal dismissed; BCCA affirmed

The Parties

• Appellant (Plaintiff): Kobe ter Neuzen, psychiatric nurse; participated in AI program 1981–January 21, 1985; approximately 33–35 AI procedures; infected with HIV as a result of the January 21, 1985 procedure; causation admitted by respondent before trial
• Respondent (Defendant): Dr. Gerald Korn, OB-GYN specialist since 1958; AI practice since 1974; over 1,600 AI patients treated; over 500 births; screened donors personally; discontinued AI program immediately upon learning of Australian cases in July 1985
• Interveners: HIV-T Group, Canadian Association of Transfused Hepatitis C Survivors, Canadian Hospital Association, Canadian Red Cross Society

Key Facts

• Critical date: January 21, 1985, the AI procedure that infected the appellant
• No HIV test was available in Canada until November 1985 (ELISA test developed in US late 1984)
• First documented HIV transmission through AI: published Lancet September 1985 (four Australian women, one donor)
• Australian government moratorium on AI: November/December 1984, not known to North American practitioners until 1985
• Dr. Mascola’s letter in NEJM (October 1983): first expression of concern about AI-HIV risk anywhere in the world, but NEJM not routinely read by gynaecologists
• The infected donor told the respondent he was heterosexual; revealed he was bisexual only after testing positive for HIV
• Jury damages: $883,800 total ($460,000 non-pecuniary; $65,000 past income; $280,000 future income; $75,000 future care; $3,800 special)
• Inflation-adjusted rough upper limit on non-pecuniary damages at time: approximately $240,000; the $460,000 award was nearly double this

The Technical versus Non-Technical Distinction (Sopinka J.)

• General rule: Where a procedure involves difficult or uncertain questions of medical treatment, or complex, scientific, or highly technical matters beyond ordinary understanding, it will NOT be open to find a standard medical practice negligent without expert evidence supporting that conclusion
• Exception: Where a standard practice fails to adopt obvious and reasonable precautions readily apparent to an ordinary finder of fact, common practice is NOT a defence; the practice may be found negligent by a jury without specialist expertise
• This is a QUESTION OF LAW for the trial judge, not a matter to be left to the jury without explicit direction
• Crits v Sylvester (the oxygen valve case) is explicitly identified as a case falling within the non-technical exception: the precaution was “easily understood by ordinary individuals” and required no clinical expertise to evaluate

The Two Aspects of the Negligence Claim

• First aspect (HIV-specific knowledge): NOT available for jury to find negligence; state of medical knowledge in January 1985 made it impossible for a reasonable North American practitioner to have known that AI posed HIV risk; technical matter requiring expert evidence; no new trial ordered on this point, and the claim fails
• Second aspect (donor screening for STDs generally): New trial ordered; evidence of standard screening practice was “sketchy”; HIV infection falls within same class of injury as other STDs; jury could fix appropriate standard on matters of basic donor screening without relying entirely on expert evidence; prudent practitioner’s duty extends to protecting patients from foreseeable class of injury even if specific disease not foreseen

The Warranty Holdings

• Sale of Goods Act: Does not apply; the AI contract was primarily one for professional medical services, and the provision of semen was incidental to, not the primary purpose of, the engagement
• Common law implied warranty: Not appropriate to imply a warranty of merchantable quality for biological substances in the medical context; physician cannot trace liability back to donor/manufacturer as commercial suppliers can; biological substances carry inherent risks; making physicians strict warranters of biological substances would make them insurers of the procedure; claim confined to negligence

Non-Pecuniary Damages (Sopinka J. majority)

• The rough upper limit from the 1978 Andrews trilogy applies to all catastrophic injuries, including novel injury profiles such as HIV infection; Lindal v Lindal confirmed that even injuries more severe than the trilogy cases do not escape the cap
• Trial judge should instruct the jury on the upper limit if damages might reasonably be assessed in the range of or exceeding the limit
• Whether or not the instruction is given, if the jury award exceeds the adjusted limit, the trial judge must reduce it, and need not wait for appeal
• L’Heureux-Dubé J. (concurring in result, dissenting on instruction): jury should determine quantum without instructions on upper limit; judge may reduce excessive awards post-verdict; jury independence in assessing damages should not be curtailed by mandatory charging on the limit

Related Articles in This Series

• Crits v Sylvester, 1956 CanLII 34 (ON CA), affirmed 1956 CanLII 29 (SCC) https://canlii.ca/t/1tvmv — establishes the governing standard of care formulation; the oxygen valve case is the canonical illustration of the Ter Neuzen non-technical exception
• Wilson v Swanson, 1956 CanLII 1 (SCC) https://canlii.ca/t/1nlkb — error in judgment doctrine and prospective assessment of standard of care; directly cited in Ter Neuzen
• Hopp v Lepp, 1980 CanLII 14 (SCC) https://canlii.ca/t/1mjv6 — the informed consent framework; disclosure failures are identified in Ter Neuzen as falling within the non-technical exception
• The 1978 Canadian Damages Trilogy — Andrews v Grand and Toy, Arnold v Teno, Thornton — establishing the non-pecuniary damages cap affirmed and applied in Ter Neuzen