What is the test for apportioning the degree of contributory negligence between two parties?

Moreover, according to s. 5 of the Contributory Negligence Act, the question of the degree of fault of each party is also a question of fact. Absent a palpable and overriding error, this court must refrain from varying the apportionment of fault unless there is a strong and exceptional reason for doing so. See Sparks et Fairfax v. Thompson, 1974 CanLII 146 (SCC), [1975] 1 S.C.R. 618; 1 N.R. 387. A simple difference of opinion with the trial judge does not constitute a strong and exceptional reason. An appellate court is only allowed to interfere when the trial judge's finding cannot reasonably be justified on the evidence.