Meghan Trainor v. Sebastien DeArcos, 2025 NBCA 131
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By: Hayley Gardner (Articled Clerk)
This decision stems from an appeal of Trainor v. DeArcos, 2024 NBKB 158, which we previously reported on in our December 2024 newsletter.
That action arose from a March 2014 motor vehicle accident in which Ms. Trainor sustained a broken heel bone, a bruised chest, and a hairline fracture in her hand. She was 20 years old at the time and had several pre-existing physical and mental heath issues. In the years following the accident, Ms. Trainor’s condition deteriorated significantly. She developed chronic pain, a TMJ disorder, and required additional surgeries to address a pre-existing condition in her leg.
The trial judge had determined that Ms. Trainor’s chronic pain, TMJ disorder, and leg surgeries were not reasonably foreseeable consequences of the collision. She concluded that legal causation had not been established and the injuries were too remote to warrant recovery. In the alternative, she found that the crumbling skull doctrine applied to Ms. Trainor and precluded recovery for these injuries.
The primary issues raised on appeal concerned whether the trial judge had erred with respect to her analysis of legal causation and her application of the crumbling skull doctrine.
Relying on the decisions in Nelson (City) v. Marchi, 2021 SCC 41, Mustapha v Culligan of Canada Ltd., 2008 SCC 27, and Edmondson et. al. v, Edmondson et. al., 2022 NBCA 4, the Court of Appeal clarified that the proper framework for determining legal causation was to consider whether it was reasonably foreseeable that, as a result of the accident, a person of ordinary fortitude could suffer the claimed injuries. The Court of Appeal found that the trial judge had departed significantly from this framework.
First, the trial judge had erred by applying a subjective standard of analysis and improperly focusing on Ms. Trainor’s particular medical history and vulnerabilities. The SCC’s decision in Mustapha provides that this must be an objective analysis.
Having found that Ms. Trainor’s chronic pain was not reasonably foreseeable, the trial judge then found the same for her TMJ disorder, seemingly on the basis that the chronic pain was the root of the TMJ. This was an incorrect analysis of legal causation, as it was based on how the injury developed rather than on whether it was reasonably foreseeable.
Finally, on the issue of the leg surgeries, the trial judge had relied on the fact that Ms. Trainor’s orthopaedic surgeon did not explicitly state that the surgeries would not have occurred “but for” the accident. The Court of Appeal noted that this was the test for factual causation, not legal causation, and it appeared that the trial judge had conflated the two analyses on this point. Ultimately, the trial judge’s findings that Ms. Trainor’s chronic pain, TMJ disorder, and right leg surgeries were not foreseeable consequences of the accident were set aside.
The trial judge’s alternative determination, that the crumbling skull doctrine applied and precluded recovery for the same injuries, was also an incorrect statement of law. This crumbling skull doctrine acknowledges that, where a plaintiff has an unstable pre-existing condition that impacts the severity of their injuries, a defendant is only liable for a portion of the damages associated with those injuries. The doctrine does not preclude a crumbling skull plaintiff from recovering damages; however, it reduces the quantum of damages available.
Additionally, the Court of Appeal determined that Ms. Trainor would be more suitably characterized as a thin skull plaintiff. This conclusion was based on the trial judge’s own factual findings that Ms. Trainor’s pre-existing conditions were relatively stable at the time of the accident.
The trial judge’s findings with respect to legal causation and the crumbling skull doctrine were set aside. The defendant was ordered to pay damages in the full amount of the trial judge’s provisional assessments under all heads of damage.
