What is the current state of the law in Canada regarding the shifting burden of liability against a carrier?

Having said that, it is important to recognize that there may be times when the policy reasons underlying the shifting burden do not exist. For instance, where an incident occurs and the operator is not even aware of the fact of the incident or the possibility of any injury, the policy foundation for the shifting burden may disappear. It may be impossible for the carrier to give an explanation at some later date because it never knew of the incident giving rise to the injury. See: Lalani v. Wilson, [1988] B.C.J. No. 2408 (Q.L.) (S.C.). In such a case, the policy and common sense reason for placing a burden on defendants may disappear.