Tripp v. Ross, 2025 MBCA 25
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By: Alexandre Doucet
On December 1, 2023, a Manitoba trial judge held that a general surgeon’s admitted negligence in performing a colonoscopy that delayed the diagnosis of colorectal cancer did not cause the patient’s premature death. Despite that ruling, the trial judge found that the delayed diagnosis caused the plaintiff pain and suffering, awarding general damages of $75,000. The Appellant, Breck Tripp, a representative of Mr. Tripp’s estate, appealed the ruling arguing the trial judge erred by not finding the Respondent, the surgeon, caused Mr. Tripp’s death on a balance of probabilities.
At issue on appeal was the legal and factual causation of Mr. Tripp’s death. The Respondent maintained that the trial judge made no errors in finding that his negligence did not legally or factually cause Mr. Tripp’s death.
The Respondent argued that the trial judge’s conclusion reflected medical evidence that Mr. Tripp’s colon cancer had already metastasized at the time of the colonoscopy, and that even if the tumor had been detected, his likelihood of survival did not meet the legal burden of proof on a balance of probabilities.
The Appellant argued that the trial judge made a palpable and overriding error by equating the legal burden of proof with statistics on five-year survival rates of different stages of colon cancer. The Appellant further submitted that the trial judge failed to draw an adverse inference against the Respondent because his negligence precluded proof of causation to a scientific certainty.
Justice Pfuetzner began her analysis by discussing the law of adverse inference on causation. Citing Benhaim v. St-German, 2016 SCC 48, she observed that, where a defendant’s negligence undermines one’s ability to prove causation, the trier of fact (i.e., trial judge) is not required to draw an adverse inference. A trial judge has discretion to conclude whether missing evidence, in this case the scientific certainty that the cancer had likely metastasized at the time it was diagnosed, should be viewed negatively upon the defendant (i.e., an adverse inference).
Justice Pfuetzner then explored whether the use of statistics at trial to determine causation was correct and appropriate. In Benhaim the Supreme Court of Canada observed that statistical evidence is of little assistance where there is a lack of an evidentiary bridge between what the statistics purport to prove and the proof sought (see paragraph 75 of Benhaim). However, in this case, the Court of Appeal found that the trial judge was entitled to rely on the statistical evidence provided as it correctly related to the likelihood of whether the cancer could have metastasized (Tripp, para 38). As there was no other means to prove whether the cancer metastasized, statistical evidence was the only reliable option of measuring those odds.
The Court of Appeal emphasized the value of deference to the trial judge’s discretionary decision. As such, Justice Pfuetzner found no legal error that would permit interference with the trial judge’s decision, dismissing the appeal.
