MAY now do; for general causation in class actions, too.
see Bartram v. GlaxoSmithKline Inc., 2012 BCSC 1804 at para. 32:
. . . [more]
 In an individual action, a plaintiff probably could not succeed by merely showing that the use of Paxil increased the risk of injury. In Clements v. Clements, , 2012 SCC 32, the Supreme Court of Canada re-affirmed the primacy of the “but for” test in proving causation and confined the alternate “material contribution” test to cases involving multiple negligent defendants where it is not possible to prove which one caused the injury. However, dicta in Clements