What is the test for assessing both contributory and quantum damages in a motor vehicle accident case?

Interestingly, in Black v. Lemon, the jury had the task of assessing both contributory causes of loss as well as quantum of damages. At trial, the jury attributed the plaintiff's continued disabilities 99 per cent to the subject accident and 1 per cent to an earlier minor accident for which they held the plaintiff 40 per cent responsible. The defendants appealed the quantum award of the jury and the plaintiff cross-appealed. Having stated the jurisdiction to interfere, this court determined not to interfere and dismissed both the appeal and the cross-appeal.