In an ICBC claim, the injured claimant must establish on the balance of probabilities that the defendant’s negligence (other driver) caused or materially contributed to an injury. The defendant’s negligence does not need to be the sole cause of the injury so long as it is part part of the cause beyond the range of de minimis. This is known as causation and it must be established before damages are assessed.
The most basic principle of the law regarding ICBC claims is that the injured claimant must be placed in the position he or she would have been in if not for the defendant’s negligence, no better and no worse. ICBC must take their victims as they find them, even if the injured claimant’s injuries are more severe than they would be for a normal person. This is known as the thin skull rule. However, ICBC need not compensate an injured claimant for any debilitating effects of a pre-existing condition that he or she would have experienced anyway even without the motor vehicle accident. If this is found, then it is open to a trial judge to reduce the award of certain damages for this measurable risk.
Our Court of Appeal in Dornan v. Silva 2021 BCCA 228 clarified the law and what evidence needed to establish the presence of a measurable risk that a pre-existing condition would result in a loss to a plaintiff in the future without a defendant’s negligence (without the motor vehicle accident) serving to reduce the award of certain heads of damage.
The Court of Appeal focused on a helpful case in this analysis of the Ontario Court of Appeal in Graham v. Rourke,  OJ No.2314.
In Graham, the plaintiff was injured in a 1984 motor vehicle accident. Previous to this, she had a long and complicated medical history including a congenital deformity of her lumbar spine that required significant spinal fusion surgeries. She also suffered from emotional difficulties requiring psychiatric treatment. She suffered serious injuries with long periods of disability from prior accidents including 2 motor vehicle accidents one of which occurred approximately 10 years prior to the subject collision. She had improved, however, by the time of the subject collision. Notably, she had returned to work which defied the odds.
In consideration of the possibility of future without accident disability, the trial judge concluded that there was no evidence that any particular future event might arise that would act to reduce the amount of compensation for future earnings and that there was “no suggestion that her present condition would, or would likely, have developed absent the accident”. The Court of Appeal focussed on a medical expert’s opinion that the plaintiff was, at the time of the subject collision, a person who was “operating on the edge of disaster”. Her vulnerability was considered so great that “even a minor accident or fall could have produced disastrous results”. This vulnerability was the critical finding in allowing the appeal and varying the damage assessments by reducing the award for loss of future earning capacity by 25%.
In Dornan, our Court of Appeal at paragraphs 74 and 75 summarized the law as follows:
• It is a matter of assessing the evidence to determine whether the hypothetical in question is a real and substantial possibility
• To support a contingency reduction, the law does not require that a measurable risk involved with wholly inherent in the plaintiff’s pre-existing condition without the need for any external event to act upon it in order to give rise to a debilitating effect
• The question is whether, given the pre-existing condition, there was a real and substantial possibility of future debilitating symptoms absent the accident
• That real and substantial possibility may arise solely from the nature of the pre-existing condition itself OR require an external event acting upon that condition – in either case, the possibility must be real and substantial, not speculative
• The measurable risk must be based on a real and substantial possibility arising from the combination and interaction of the pre-existing condition and the external event
• In the vast majority of cases, the risks commonly encountered on this rather dangerous planet will not suffice to establish a real and substantial possibility (see para. 77 for examples of speculative risks) – any affect these speculative risks may have on the individual’s pre-existing condition would be speculative, not real and substantial possibilities and do not give risk to a measurable risk at least in the absence of being combined with some extreme vulnerability
In Graham, her pre-existing condition was such that, but simply existing, she was operating on the edge of disaster in that she had extreme vulnerability. The risk of further injury was, therefore, measurable because it could be safely predicted that almost anything she did would trigger it.