Executive Summary: Key Legal and Evidentiary Issues

• Extent to which a low-speed rear-end collision caused the plaintiff’s profound psychological and functional decline despite minimal vehicle damage.
• Proper application of negative contingency deductions where the plaintiff has significant pre-existing medical conditions, including Addison’s disease.
• Weight to be given to competing expert evidence on causation, particularly psychiatric, neurological, and physiatric opinions versus limited treating-physician records.
• Whether an “extreme psychological vulnerability” to developing outsized symptomatology justified a high (75%) specific negative contingency deduction.
• Legitimacy of applying a negative contingency deduction to past wage loss and agreed special damages, rather than only to future-oriented heads of damage.
• Appellate review of damages where a trial judge’s contingency assessment is not grounded in the structured Dornan framework or an evidentiary basis for likelihood.

Background and facts of the case

The case arises from a motor vehicle accident on July 6, 2018, in North Vancouver. The appellant, Kristina Mariotto, was stopped in traffic when her vehicle was struck from behind at low speed by a vehicle driven by the defendant, Joan Rowntree, now represented by her estate. The collision was minor, causing almost no damage to either vehicle, and the airbags did not deploy. Immediately after the accident, Ms. Mariotto remembered speaking with Mrs. Rowntree, showed concern for her, drove herself home, and initially reported only neck and lower back pain when she later sought medical attention. Prior to the accident, Ms. Mariotto, almost 51 at the time, had a long and stable employment history in dental offices and for her husband’s engineering company. She had trained as a dental receptionist, worked her way up to office manager for an orthodontist, and later moved to a closer dental practice in North Vancouver. She was also assisting with bookkeeping and office management for her husband’s company. Outside work, she led an active life, going to the gym, playing tennis and golf, cycling, dancing, and helping with home and gardening projects, and had a socially engaged lifestyle with her husband. Medically, she had a history of several conditions: perimenopausal symptoms, severe asthma, episodic migraines, chronic obstructive pulmonary disease, gastroesophageal reflux disease, B-12 deficiency, hypothyroidism and, crucially, Addison’s disease diagnosed around 2014. Addison’s, a rare disorder affecting adrenal steroid production, was being actively managed by an endocrinologist with steroid medication. Despite this complex medical background, both she and her husband described her pre-accident health issues as manageable and not functionally disabling; she was working and carrying out her normal responsibilities. Following the accident, her condition deteriorated markedly. The trial judge, after observing her over two days of testimony, accepted that she was not feigning symptoms. He found that her life had “substantially unravelled” and that she was now “seriously and demonstrably” incapacitated, noting she was scattered and tangential in thinking, quickly fatigued, emotionally labile, embarrassed by her cognitive difficulties, aware of the strain on key relationships, and anxious about her future. Lay witnesses—her husband and sister—were found to be credible and compelling, describing a precipitous decline in her ability to function normally in any aspect of life after the collision, with new and troubling mental and emotional symptoms that had not been present before.

Evidence at trial and competing medical theories

At trial, liability was admitted, so the case proceeded solely on damages, focusing on causation and quantum. The plaintiff’s evidentiary foundation included her own testimony, her husband and sister, and her treating occupational therapist, whose evidence was largely corroborative. On the expert side, she called an occupational therapist, a psychiatrist (Dr. Spivak), a physiatrist (Dr. Caillier), and an economist. The defence called a collision engineer, the endodontist who had employed her shortly before the accident, and a neurologist (Dr. Webber). Two additional defence experts—a biomechanical engineer and an endocrinologist—were retained but never called, and none of her treating doctors, including her family physician, endocrinologist or neuropsychologist, testified, despite the obvious centrality of Addison’s disease and her broader medical picture. The plaintiff advanced a theory that she had suffered a mild traumatic brain injury (concussion) in the collision, leading to chronic post-traumatic headaches and cognitive dysfunction. Drs. Spivak and Caillier supported aspects of this narrative, linking her current constellation of fatigue, pain, headaches, and cognitive issues to the motor vehicle collision. The defence countered that her complicated medical history, particularly Addison’s disease, explained her symptoms and that the minor rear-end impact could not plausibly have caused the profound and persisting deficits she described. The trial judge rejected both sides’ primary theories. He was not persuaded that the dynamics of the low-speed impact could have produced a concussion or mild traumatic brain injury, preferring the neurologist Dr. Webber’s evidence over the plaintiff’s experts on that point. At the same time, he would not accept the defence position that her condition was entirely attributable to Addison’s disease, given the scant direct endocrinological evidence. Instead, he concluded that her current symptoms were “multifactorial,” arising from her complex medical profile, with the accident as one, but not necessarily the dominant, component. Crucially, the trial judge accepted Dr. Spivak’s diagnosis of somatic symptom disorder with predominant pain. He understood this to mean that Ms. Mariotto genuinely believed in and was committed to her perception of her post-accident symptoms, whether their physical cause was real or not, and that she experienced a degree of functional impairment far greater than would ordinarily be expected from the physical insult itself. This diagnosis, combined with the accepted lay evidence, led the trial judge to find that the accident operated as a catalyst: immediately after a minor collision, her functionality “went rapidly and sharply downhill” and she did not improve, producing what he characterized as “outsized” present-day symptomology.

Trial judgment on damages and negative contingencies

At first instance (2025 BCSC 1387), the trial judge accepted that the accident played some role in producing the serious psychological deficits and functional disability now seen in Ms. Mariotto, but he considered it “inconceivable” that her condition was entirely attributable to the defendant’s negligence. Emphasizing the principle that a defendant need not put a plaintiff in a better position than her original one, he reasoned that she must have been predisposed to significant psychological injury by any reasonably minor unexpected physical force or shock, and that there was a “very substantial likelihood” she would have ended up in her current state through some other everyday mishap even without this particular accident. Against that backdrop, he determined that only 25% of her present condition should be attributed to the accident, applying a 75% “contingency discount” across all heads of damage—non-pecuniary damages, past wage loss, loss of future earning capacity, future care costs, and special damages. Before this discount, he assessed full damages at approximately $1.6 million. After applying the 75% negative contingency to every head, he awarded net damages of $378,192.98, including $50,000 in non-pecuniary damages, $82,040.50 in past wage loss, $156,993 for loss of future earning capacity, $84,749.25 in cost of future care, and $4,410.23 in special damages. The plaintiff appealed, arguing that the trial judge either should not have applied a negative contingency at all, or that, if one were appropriate, the 75% level was not supported by the evidence or by the proper legal framework. She further contended that the judge erred in applying the same contingency to past wage loss and to agreed special damages, which relate to actual past expenses, not speculative future risks.

Appellate framework on contingencies and standard of review

On appeal, the British Columbia Court of Appeal recognized that damage awards are subject to considerable deference. Appellate intervention is limited to situations where the trial judge commits a palpable and overriding error of fact, proceeds on a wrong principle, or arrives at an award so inordinately high or low as to represent a wholly erroneous estimate of damages. Against that deferential standard, the Court focused on the specific legal framework governing positive and negative contingencies distilled in prior authority such as Dornan v. Silva, as well as subsequent cases including Lamarque, Murphy, Sharma, Lo, and Steinlauf. Under Dornan, the Court distinguished general contingencies—ordinary vicissitudes of life applying to everyone—from specific contingencies, which are unique to the plaintiff, such as a particular pre-existing medical condition. A negative specific contingency based on pre-existing conditions is only justified where the evidence establishes a “real and substantial possibility” that the condition would have detrimentally affected the plaintiff in any event. Once such a possibility is found, the court must then assess the relative likelihood of it materializing and adjust the award accordingly. The burden of establishing this real and substantial possibility rests on the party asserting it—here, the defendant. Importantly, Dornan emphasized that not every risk on “this rather dangerous planet” translates into a measurable contingency. Everyday mishaps—minor falls, recreational injuries, garden accidents, low-impact collisions—do not, without more, create a real and substantial possibility that a given plaintiff will reach the same state of disability; such effects are speculative unless coupled with some “extreme vulnerability.” The Court of Appeal noted that while the trial judge cited the broad principle that a defendant should not compensate for inevitable consequences of pre-existing conditions, he did not explicitly apply Dornan’s two-step “real and substantial possibility/relative likelihood” analysis when fixing the 75% deduction.

Extreme psychological vulnerability and the appropriate deduction

The key appellate question became whether the evidence supported any specific negative contingency and, if so, whether a 75% deduction was justified on a proper evidentiary and legal footing. The Court accepted that, although the trial judge did not use the term, the evidence he accepted effectively placed Ms. Mariotto in the “extreme vulnerability” category. This was not because of her Addison’s disease or other physical ailments: the record did not show that those conditions alone created an extreme risk of her current psychological collapse. Rather, it was the somatic symptom disorder diagnosis, endorsed by Dr. Spivak and implicitly accepted by Dr. Webber who deferred to psychiatry on mental health issues, that grounded the finding of extreme psychological vulnerability. On the trial judge’s findings, Ms. Mariotto’s particular vulnerability meant that even relatively minor physical events could trigger “outsized symptomology,” suggesting a genuine risk that some other trivial mishap might have led to a similar state even absent the Rowntree collision. On that basis, the Court held there was evidentiary support for recognizing a negative specific contingency: a real and substantial possibility that she would have ended up in her present condition regardless of this accident. However, the Court rejected the magnitude of the trial judge’s 75% discount. It held that this figure was “untethered” to evidence of how likely it was that another everyday mishap would actually occur and trigger her extreme vulnerability. The judge’s suggestion that some other minor transfer of force would likely have led to the same outcome rested more on intuition than on a quantified or inferentially supported assessment of likelihood. The appellate judges emphasized that Dornan requires both a real and substantial possibility and an assessment of its relative probability, not simply a broad sense that something “could well have happened.” Examining the record, the Court pointed to countervailing facts: Ms. Mariotto had been in prior motor vehicle accidents without comparable consequences, had experienced other mishaps such as a dog-walking fall, and had returned to work after an Addison’s-related medical leave just months before the accident. These events suggested that, while vulnerable, she was not inevitably destined to reach her current state, and that the risk of some future triggering mishap was materially lower than the trial judge assumed. Balancing these considerations, the Court concluded that a negative contingency was appropriate but that, in light of the actual probabilities indicated by her history, it should be set at 25%, not 75%. In other words, the Court found a real risk that she might have developed similar disabling symptoms in any event, but characterized that risk as relatively unlikely, not overwhelmingly so.

Treatment of past loss, special damages, and future care

The Court of Appeal also addressed the scope of the contingency’s application across different heads of damage. It agreed with the appellant that subjecting special damages to the negative contingency was an error in principle. Special damages represent past, out-of-pocket expenses actually incurred, and in this case were uncontested. They are not speculative future losses and therefore should not be reduced by a forward-looking contingency that is premised on the risk of a future event. The Court relied on prior authority confirming that such past special expenses should not be adjusted for the sort of future risk contemplated by Dornan and related cases. By contrast, the Court held that the same logic did not fully apply to all elements of the cost of future care. To the extent future care requirements flow from the plaintiff’s ongoing symptoms, and bearing in mind the possibility that she might have reached a similar condition even without this accident, those future-oriented costs remain subject to a negative contingency—albeit the reduced 25% level. Put differently, while the trial judge erred in the scale of the deduction, the concept of applying a specific negative contingency to future-looking heads of damage, including future care needs, was sound. Similarly, non-pecuniary damages, past wage loss, and loss of future earning capacity—all tied in varying degrees to her present and future disability—could be properly adjusted for the 25% specific contingency reflecting the real but relatively unlikely prospect that she would have ended up similarly disabled in any event of the defendant’s negligence.

Final appellate outcome and adjusted award

Having identified errors in the trial judge’s application of the contingency framework and his treatment of specific heads of damages, the Court of Appeal exercised its own judgment to adjust the award. It allowed the appeal, set aside the 75% negative contingency, and replaced it with a 25% deduction applicable to non-pecuniary damages, past wage loss, loss of income earning capacity, and the cost of future care, while excluding special damages from any reduction. Recalculating on that basis, the Court fixed the damages at $1,138,989.17, composed of $150,000 in non-pecuniary damages, $246,121.50 in past wage loss, $470,979 for loss of income earning capacity, $254,247.75 for cost of future care, and $17,640.92 in unreduced special damages. In doing so, the Court reaffirmed that specific negative contingencies must rest on both a demonstrated real and substantial possibility and a proportionate assessment of the likelihood of that possibility materializing. In the end result, the appeal was allowed and the plaintiff, Kristina Mariotto, emerged as the successful party, with the appellate court significantly increasing her compensation to a total monetary award of $1,138,989.17 in damages in her favour.