What is the test for determining whether a defendant contributed to a plaintiff’s injury?

The defendant’s contribution must be material in that there is a substantial connection between the accident and the injury beyond a de minimus range: Farrant v. Laktin, 2011 BCCA 336 at paras. 9-11. If the injury is divisible, a plaintiff can recover from the defendant only the damages attributable to the injury caused or contributed to by that defendant. If the injury is indivisible, a plaintiff can recover from the defendant 100% of the damages attributable to the injury caused or contributed to by that defendant, regardless of the contribution to the injury by others: Athey, at para. 24.