Proving that someone was careless is only part of a negligence case. The plaintiff must also connect that carelessness to the harm. In Hemmings v. Padmore, 2026 SCC 34, released October 23, 2026, the Supreme Court of Canada used an Ontario medical negligence appeal "to clarify the analytical roles that factual causation and remoteness play in the negligence analysis" (para. 3). Its message: these are two separate questions, and each must be answered on its own terms (para. 43).
Note: the Court's text is subject to editorial revision before it is published in final form in the Supreme Court Reports. Quotations below are from the version released October 23, 2026.
The decision at a glance
Citation: Hemmings v. Padmore, 2026 SCC 34 (Supreme Court of Canada). Judgment October 23, 2026.
Official text: Supreme Court of Canada decision
Reasons: joint reasons of Rowe and O'Bonsawin JJ., Jamal J. concurring (paras. 1-164). Martin J., with Karakatsanis and Moreau JJ., dissented in part (paras. 165-247). Wagner C.J. dissented in part (paras. 248-290).
Result: both appeals dismissed (para. 4).
What happened
A woman suffered a cardiac arrest during an emergency caesarean section at a hospital and was left with severe and permanent brain damage. She (through her litigation guardian) and her family sued several of her healthcare providers and the hospital (para. 1). The trial judge found two doctors and the hospital liable. The Court of Appeal for Ontario dismissed the actions against one doctor and the hospital but upheld the judgment against the anesthesiologist (para. 2). Both the family and the anesthesiologist appealed to the Supreme Court (para. 3).
The joint reasons dismissed both appeals. They found the trial judge erred in his factual causation analysis for a hospital nurse and in his remoteness analysis for both that nurse and her obstetrician. The plaintiff's injuries were "too remote" from their conduct to hold either liable (para. 4). The judgment against the anesthesiologist stood (paras. 5, 158).
The Court was divided. Martin J., with Karakatsanis and Moreau JJ., would have restored the trial judgment against the obstetrician (para. 165). Wagner C.J. would have allowed the anesthesiologist's appeal as well and set aside every finding of liability (para. 290).
What the Court said about the law
Two inquiries, not one. A negligence plaintiff must show a duty of care, a breach, damage, and that the damage was caused "in fact and in law" by the breach. That causation requirement "entails two distinct inquiries": whether the conduct was the factual cause of the injury, and whether the injury is too remote to assign liability (para. 42).
Keep them apart. It is "essential that factual causation and remoteness of damage remain analytically distinct and be treated separately" (para. 43). Only factual causation is a strictly causal question. Remoteness "is a normative inquiry" into whether the connection between the wrong and the injury is close enough that the defendant should be liable (para. 43).
One name for remoteness. The Court noted that remoteness has also been called "legal causation", "proximate cause", "proximity" or "cause-in-law". These "all refer to the same element", and the joint reasons refer only to remoteness (para. 43). Wagner C.J. "wholeheartedly" endorsed the choice "to consign the language of 'legal causation' to the dustbin of history" (para. 289).
Factual causation: the "but for" test. The plaintiff must prove, on a balance of probabilities, that "but for" the defendant's negligence the injury would not have occurred (para. 45). The conduct must be a necessary cause, "but not necessarily the sole cause". Where several actors' negligence is each a necessary cause, they are jointly and severally liable (para. 46). Causation "need not be proven with scientific precision", and the test is applied "in a robust, common-sense fashion" (para. 47). The burden stays with the plaintiff even when the defendant says the injury would have happened anyway (para. 48).
When to spell out the counterfactual. In simple cases, a court can infer causation "without difficulty" and may not need to explicitly reject the alternative (para. 49). In harder cases, such as those with multiple defendants, long gaps in time, competing theories or conflicting evidence, the court may need an explicit counterfactual analysis: take out the defendant's negligent conduct and ask whether the plaintiff would still have suffered the same injury (paras. 50-51).
Remoteness: what was reasonably foreseeable. A defendant is liable only for consequences it could reasonably have foreseen at the time of the breach (para. 70). There must have been "a real risk or probability, one greater than a mere possibility", that that type of injury could occur (para. 71). The defendant "need not have foreseen the precise concatenation or sequence of events" (para. 72).
How appeals review these findings. Factual causation is a finding of fact, reviewed for palpable and overriding error. But "failing to undertake the counterfactual analysis needed to properly apply the 'but for' test is a legal error" reviewed for correctness (para. 87). Remoteness is "a question of mixed fact and law" (para. 88).
What changed
The tests are not new; the joint reasons build on earlier cases such as Clements and Mustapha (paras. 45, 70). What changes is the discipline required in applying them: courts must analyze factual causation and remoteness separately (para. 43) and, in complex cases, may need to do an explicit counterfactual analysis (paras. 50-51). The joint reasons also settle on a single name, saying they "will refer only to remoteness" (para. 43). Skipping the counterfactual analysis can be an error of law (para. 87).
Who this affects
Plaintiffs in negligence claims, who must prove factual causation and also show the type of injury was reasonably foreseeable (paras. 45, 71).
Defendants and their insurers, who can contest either element (paras. 4, 48).
Parties in multi-defendant cases, where each defendant's role may need its own counterfactual analysis (paras. 50-51).
Practical takeaways
Treat causation and remoteness as two separate questions, and prove each (paras. 42-43).
Factual causation is decided on the evidence as a whole, robustly and with common sense, not with scientific precision (para. 47).
In complex cases, build the counterfactual into the evidence and the argument (paras. 50-51).
Foreseeability is about the type of harm, not the exact sequence of events (para. 72).
Frequently asked questions
What is the difference between causation and remoteness?
Factual causation asks whether the defendant's conduct actually caused the injury. Remoteness asks whether the injury is too remote from that conduct for the defendant to be held liable (para. 42). The Supreme Court said the two must be kept analytically distinct (para. 43).
What is the "but for" test?
The plaintiff must show on a balance of probabilities that, but for the defendant's negligence, the injury would not have occurred. The conduct must be a necessary cause, but not necessarily the only one (paras. 45-46).
Does a defendant have to foresee exactly how the harm happened?
No. The defendant need not have foreseen the precise sequence of events; the question is whether there was a real risk of the type of harm suffered (paras. 71-72).
What is "legal causation"?
It is another name for remoteness. The Court said terms like "legal causation" and "proximate cause" all refer to the same element and used only "remoteness" (para. 43).
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Written by the lawyers of Francis Mehr LLP. Published October 30, 2026; reflects the judgment of October 23, 2026, which is subject to editorial revision. This post is general information, not legal advice.
