In Lewis (Guardian ad litem of) V. British Columbia, [Note 50:

[1997] 3 S.C.R. 1145 [Lewis]. See also Mochinski v. Trendline Industries Ltd., [1997] 3 S.C.R. 1176.] the Supreme Court, in judgments delivered by Cory J. and McLachlin J., began the task of seeking some unifying and guiding principle. In that case, the defendant province hired an independent contractor to remove protruding rocks from a cliff face above a highway. The work was carried out negligently by the contractor and a rock that ought to have been removed fell onto the highway, killing a motorist. The defendant was under a duty of care to maintain the highway in the exercise of its statutory powers. It argued, nonetheless, that it had delegated the task to an independent contractor and it was not liable for its negligence. The Court disagreed. The duty of care was non-delegable and the defendant was liable because care had not been taken. The Court held that the issue of whether or not a duty of care is non-delegable turns on the nature of the relationship between the defendant employer and the plaintiff, the nature of the duty of care, and the surrounding circumstances. There must be some special relationship or special element in the relationship such as a special undertaking of care or a special responsibility for the plaintiff which justifies the higher obligation to ensure that care is taken. A number of factors in Lewis supported the conclusion that the duty of care was not delegable. First, the authorizing legislative provisions gave the ultimate power, control, and authority to maintain and repair highways to the defendant province. Second, members of the public cannot easily determine if highway maintenance is done properly and they are, therefore, particularly dependent on the province for their safety. Finally, the public reasonably expects that the province will remain responsible for the condition of the highway even if private contractors do the work.

The evolution of non-delegable duties from categories to principle may signal some expansion of non-delegable duties in other situations. In B.(K.L.) v. British Columbia, [Note 51: [1998] 10 W.W.R. 348 (B.C.S.C.).] for example, it was held that the Crown owes a non-delegable duty of care to children in its custody and under its guardianship. Children in institutional care are in a vulner- able position and it is reasonable to impose such a duty where the Crown has assumed care of, control over, and responsibility for them. Lewis may also anticipate the imposition of a non-delegable duty of care on hospitals to ensure that care and skill are exercised in the treatment of its patients. Some years ago this view was rejected by the Ontario Court of Appeal in Yepremian v. Scarborough General Hospital. [Note 52: (1980), 28 O.R. (2d) 494 (C.A.).] It was held that the defendant hospital was not vicariously liable for non-staff doctors who had hospital privileges: they are independent contractors for whom the hospital is not liable. Lewis gives new life to the argument that the hospital has a special relationship with its patients. It undertakes a responsibility for its patients who are vulner- able and dependent on the institution. The reasonable expectation of patients is that the hospital has the ultimate responsibility for the quality of care delivered and, consequently, its duty of care may not be delegated to physicians, surgeons, food suppliers, providers of equipment, suppliers of pharmaceuticals, and other independent contractors. This kind of reasoning may also be applicable to school boards in respect of the safety of their students.

The responsibility of an employer in respect of a non-delegable duty is confined to wrongful acts in the performance of the task or work that the independent contractor was hired to do. The employer is not liable for collateral or casual acts of negligence. [Note 53: J.G. Fleming, The Law of Torts, 9th ed. (Sydney: LBC Information Services, 1998), at 437.] This is another elusive concept. It is designed to impose a narrower responsibility than the phrase "course of employment" used in respect of employees. Nevertheless, the negligent act must be quite discrete and severable from the assigned task before the employer escapes responsibility.