Background
Jessica Rathwell was injured in a 2017 rear-end motor vehicle accident for which the respondent, Travis Shorey, admitted liability. The trial proceeded solely on the assessment of damages. Ms. Rathwell, who had a history of pre-existing conditions including migraines, anxiety, and depression, claimed the accident caused chronic pain, a mild traumatic brain injury (MTBI), and exacerbated her psychological issues, seeking over $3 million in damages.
The trial judge found that while the accident caused soft tissue injuries and worsened her anxiety, it did not cause an MTBI. The judge noted that Ms. Rathwell had a “distorted perception of her own disability” and that psychological factors were reinforcing her symptoms. Based on these findings and her pre-existing vulnerabilities, the judge awarded a total of approximately $544,000.
Crucially, the trial judge applied significant negative contingency deductions to the awards for lost earning capacity: 30% for past loss and 35% for future loss. These deductions were based on the finding that there was a “real and substantial possibility” that Ms. Rathwell’s pre-existing conditions would have negatively impacted her employment even if the accident had never occurred.
The Court’s Holding
The Court of Appeal for British Columbia largely upheld the trial judge’s decision, dismissing most of Ms. Rathwell’s grounds of appeal. The court found there was “ample evidence” supporting the trial judge’s conclusion that Ms. Rathwell’s significant pre-existing physical and psychological vulnerabilities created a real and substantial possibility she would have missed work and earned less, independent of the accident. The 30% and 35% contingency deductions were therefore justified.
The appellate court also affirmed the trial judge’s finding that Ms. Rathwell did not sustain a concussion or MTBI, and thus was not entitled to damages for related treatments. The court deferred to the trial judge’s assessment of the conflicting expert medical testimony and her findings regarding Ms. Rathwell’s credibility.
However, the appeal was allowed on one narrow ground. The Court of Appeal determined that the trial judge had made a calculation error by double-counting a maternity leave. The judge had already accounted for the leave in the award for *past* loss of income but then incorrectly deducted for it again when assessing the *future* loss of earning capacity. The matter was sent back to have the damages award adjusted to correct this specific error.
Key Takeaways
- Courts can apply substantial negative contingency deductions to damage awards if there is evidence of a “real and substantial possibility” that a plaintiff’s pre-existing conditions would have limited their earnings even without the defendant’s negligence.
- A trial judge’s findings of fact, assessment of expert evidence, and evaluation of a plaintiff’s credibility are entitled to significant deference and will not be overturned on appeal absent a palpable and overriding error.
- While a defendant must take their victim as they find them (the “thin skull” rule), they are not liable for the effects of pre-existing conditions that would have occurred anyway (the “crumbling skull” principle).
- A simple mathematical or accounting error in a damages calculation, such as deducting for the same event in two different award categories, constitutes a reversible error of law.
Why It Matters
This decision provides a strong affirmation of the “crumbling skull” defence in Canadian tort law. It clarifies that a defendant is responsible only for the additional harm caused by their negligence, not for the pre-existing frailties of the plaintiff that would have caused similar outcomes regardless of the tortious act. The court’s acceptance of large, evidence-based contingency deductions demonstrates how this principle is applied in practice to ensure a fair and proportionate damages award.
For personal injury lawyers, this case underscores the critical role of expert medical evidence in establishing or challenging the likely trajectory of a plaintiff’s life absent the injury. It confirms that a well-reasoned contingency analysis by a trial judge, grounded in a solid evidentiary record, is difficult to challenge on appeal.