What is the test for reducing damages when a plaintiff fails to follow a rehabilitative program?

In Antoniali v. Massey, 2008 BCSC 1085 at para. 31, Preston J. formulated a helpful set of criteria to determine when an award of damages should be reduced “by application of the principle that a plaintiff has a positive duty to mitigate his or her injuries”. Adapted for use beyond the particular circumstances of that case, these criteria require a defendant to establish: 1. That a rehabilitative program would have reduced or eliminated the effect of the injuries; 2. That a reasonable plaintiff in the same circumstances would have followed such a program; 3. That the plaintiff unreasonably failed to follow such a program; and 4. The extent to which the plaintiff’s damages would have been reduced if he or she had followed such a program.