What is the test for failure to mitigate?

As for the former point, I agree with what was said in Turner v. Coblenz, 2008 BCSC 1801, [2008] B.C.J. No. 2561, para. 101: The defendant bears the onus of proving the essential elements of failure to mitigate, which are the following: (a) That a qualified medical expert recommended that a plaintiff undergo a particular form of treatment; (b) That the plaintiff failed or refused to take the recommended treatment although it was available to him or her; and (c) That the plaintiff’s refusal or failure was unreasonable, in that if the plaintiff had taken the recommended treatment, there is some likelihood that he or she would have received substantial benefit from it, and the treatment would not expose the plaintiff to significant risk.