How should litigants and trial judges approach the causation analysis in negligence cases?
In Hemmings v. Padmore, 2026 SCC 34, released on October 23, 2026, the Supreme Court of Canada clarified and restated the law of causation in negligence cases, including complex medical negligence cases. The decision underscores the distinct roles of factual causation and remoteness and the need to address each separately in the causation analysis.
BLG is proud to have represented HIROC and the hospital in successfully responding to this appeal. The BLG team included Cindy D. Clarke, Kirsten Crain, Daniel Girlando, Alysha Flipse, and others.
Key takeaways
- Causation entails two distinct inquiries: factual causation and remoteness are separate inquiries.
- The language of “legal causation” (and related terms such as “proximate cause”, “proximity” or “cause-in-law”) is consigned to the “dustbin of history” – the correct term is remoteness.
- Factual causation asks whether the defendant’s breach caused the injury as a matter of fact. Under the usual “but for” test, the plaintiff must establish on a balance of probabilities that the injury would not have occurred had the defendant met the standard of care. This counterfactual analysis asks whether appropriate care would have avoided the injury, not merely changed the sequence of events.
- Remoteness asks whether there is a sufficient connection between the defendant’s wrongful conduct and the plaintiff’s injuries such that the defendant should be liable. This inquiry can limit legal responsibility, even where there is factual causation.
- The remoteness inquiry is context-specific and rooted in corrective justice. It asks whether there was a “real risk” of harm, which requires the court to consider whether the risk is one that a reasonable person ought to have foreseen and taken reasonable precautions to prevent.
Background
Sophia Hemmings suffered a cardiac arrest following anesthetic complications during an emergency caesarean section and sustained severe, permanent brain damage. She and her family sued the hospital and several healthcare providers involved in her care, including Dr. Padmore, the obstetrician who treated her during much of her pregnancy; Drs. Peng and O’Brien, the obstetricians involved in her care around the delivery; and Dr. Jamensky, the anesthesiologist who administered general anesthesia during the operation. The claim against the hospital included vicarious liability for the alleged negligence of a nurse, who provided telephone advice to Ms. Hemmings 12 days before the cardiac arrest.
The trial judge found the hospital, Dr. Padmore, who provided prenatal care, and Dr. Jamensky, the anesthesiologist, liable. The Court of Appeal set aside the findings of liability against the hospital and Dr. Padmore but upheld the judgment against Dr. Jamensky.
Supreme Court dismisses the appeal and clarifies causation
The Supreme Court, in a divided decision involving three sets of reasons, dismissed both the family’s appeal and Dr. Jamensky’s appeal, confirming that the hospital and Dr. Padmore were not liable, while upholding the finding of liability against the anesthesiologist, Dr. Jamensky.
The majority reasons were penned by Justices Rowe and O’Bonsawin (with Justice Jamal concurring). Justice Martin (with Justices Karakatsanis and Moreau concurring) agreed with the majority’s disposition of Dr. Jamensky’s appeal, but dissented in part on the family’s appeal, and would have restored liability against Dr. Padmore. Chief Justice Wagner agreed with the majority’s disposition of the family’s appeal and specifically endorsed the majority’s statement of the law relating to factual causation and remoteness, but would have allowed Dr. Jamensky’s appeal.
Clarifying causation
The decision reinforces that a successful plaintiff must prove both that the defendant’s breach of the standard of care was the factual cause of the damages (“factual causation”), and that the injuries are not too remote from the defendant’s conduct to assign liability (“remoteness of damage”).
Factual causation ordinarily asks whether, on a balance of probabilities, the injury would have occurred but for the defendant’s negligent conduct. This is a “strictly causal” question. The defendant’s conduct must be a necessary, but not necessarily the sole cause, of the plaintiff’s injury. In complex cases, the court may need to engage in an explicit counterfactual analysis to determine if the injury would have occurred even if the defendant’s conduct had not fallen below the standard of care. However, in other, simpler cases, it may be inferred from a finding of factual causation that the trial judge rejected the counterfactual. The majority acknowledged that medical negligence cases often raise complex medico-legal causation issues, which would require the trial judge to offer more explicit analysis.
Remoteness, previously referred to as legal causation, asks whether the injury suffered was a reasonably foreseeable consequence of the breach. This is a normative inquiry, which asks if there is a sufficient connection between the defendant’s wrongful conduct and the plaintiff’s injuries for the defendant to be liable.
All members of the Court agreed that these are two distinct inquiries, and that going forward, the latter inquiry should be referred to as “remoteness”. The Court discarded previously used terms, such as “legal causation”, “proximate cause”, “proximity”, or “cause-in-law”.
Guiding principles for the remoteness analysis
The majority set out three guiding principles for the remoteness analysis. First, a negligent defendant can only be liable for those consequences that they could have reasonably foreseen at the time of their breach. Second, there must have been a real risk or probability that the type of injury could occur such that a reasonable person would have taken reasonable precautions to prevent it. Third, although the defendant need not have foreseen the precise sequence of events leading to injury, the type of accident or incident must have been foreseeable. The focus must remain on the actual injury suffered by the plaintiff.
The Court emphasized the corrective justice orientation of all tort law, including negligence. The remoteness inquiry ensures that a defendant is only liable for the plaintiff’s injuries “if the probability that those injuries would occur was something the defendant ought to have considered and taken precautions to prevent”. This is a context-specific inquiry, which will be driven by both the degree of harm that is foreseeable and the costs associated with preventing the risk of that harm. Remoteness is not applied to address public policy concerns.
While the remoteness inquiry has been described as demanding value judgments, the majority confirmed that it is not merely a matter of fairness and public policy, and rejected the Hemmings family’s arguments that liability can be determined on the basis of general policy considerations. This would introduce unacceptable uncertainty into the analysis.
The role of reasonable foreseeability in the negligence analysis
While reasonable foreseeability plays a significant role in the remoteness inquiry, this concept also plays a role in establishing whether the defendant owes the plaintiff a duty of care.
The majority clarified that while the concept of reasonable foreseeability is applied at both the duty of care and remoteness stages, it plays a different role in each inquiry. At the duty of care stage, the focus is on the type of harm and class of plaintiff. In contrast, at the causation stage, the focus is on whether there is a sufficient connection between the defendant’s wrongful conduct and the particular injury suffered by the plaintiff.
Scope of the reasonably foreseeable harm
The Court also grappled with how to define the injury that must be reasonably foreseeable for the purposes of the remoteness inquiry.
The majority observed that describing the injury too broadly (such as risk of “physical injury”) or too narrowly is improper. The former would risk creating unlimited liability, while the latter would risk immunizing defendants from liability.
In the context of this case, the majority characterized Ms. Hemmings’ injuries as those resulting from anesthetic complications, namely, cardiac arrest and the resulting brain injury. The majority rejected the family’s argument that all that needed to be reasonably foreseen was “physical injury”. This would cast the net too wide, and result in defendants being held liable for virtually all consequences, regardless of whether there was a real risk of that consequence occurring.
Application: All judges agreed the hospital should not be held liable, but disagreed with respect to the liability of the physicians
Applying the legal principles, the Court unanimously dismissed the appeal involving the hospital, with all seven judges agreeing that the hospital should not be held liable.
The majority held that the trial judge erred in assessing whether the hospital was a factual cause of Ms. Hemmings’ injuries, and that given the indirect relationship between the nurse’s negligent conduct and Ms. Hemmings’ injury, suffered 12 days later, the trial judge was required to address the counterfactual directly. The majority also found that the trial judge erred in the remoteness inquiry by failing to reconcile his findings that Ms. Hemmings’ injuries were reasonably foreseeable to the nurse and to Dr. Padmore, but not to Dr. O’Brien, an obstetrician who conducted Ms. Hemmings’ caesarian section, and who had more information regarding Ms. Hemmings’ risk factors than either Dr. Padmore or the nurse. In the majority’s view, these findings were logically inconsistent.
Justice Martin agreed that the injuries suffered by Ms. Hemmings did not fall within the scope of the risk created by the nurse’s negligence, and so it was not possible to find the hospital liable in negligence.
The Court was more divided in its assessment of the claims against the physicians. With respect to Dr. Padmore, the majority held that the expert evidence did not support that the risk of anesthetic complications arising from obesity (one of Ms. Hemmings’ risk factors) were reasonably foreseeable, with two experts testifying that they would not inform a pregnant patient of the risks of anesthetic complication. In contrast, Justice Martin found that Ms. Hemmings’ injuries were a “pregnancy-related risk” that were not too remote, such that Dr. Padmore ought to have been liable. She held that Dr. Padmore’s negligence, in failing to discuss Ms. Hemmings’ high risk factors and the possibility of terminating the pregnancy, created a broad scope of risk that Ms. Hemmings’ elevated pregnancy-related risk factors (including the risk of anesthetic complications) would materialize.
With respect to Dr. Jamensky, the majority held that the trial judge’s reasons were sufficient, when reviewed functionally and contextually, and found no error in the judge’s analysis of factual causation. Dr. Jamensky’s negligent act (converting to general anesthetic) was in close temporal proximity and clearly connected to Ms. Hemmings’ injury, and as such an explicit counterfactual analysis was not required. In contrast, Chief Justice Wagner found that the trial judge erred by conflating the factual causation and remoteness analyses, by assessing whether Dr. Jamensky was a “direct cause”, rather than a necessary cause, of Ms. Hemmings’ injuries, and by failing to conduct the required counterfactual analysis.
The split decisions with respect to the liability of the defendant physicians underscore the complexity of conducting a causation analysis, even where the governing legal principles are settled.
Hemmings is a welcome restatement of the law of causation, and will have a far-reaching impact well beyond the medical context.
By Borden Ladner Gervais LLP “BLG” >>
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