Can a claim for collateral benefits be deducted from an award for lost wages?

Counsel for the plaintiff referred to Cunningham v. Wheeler, 1994 CanLII 120 (SCC), [1994] 1 S.C.R. 359 where the majority held that where there is evidence that an employee has paid in some manner for disability benefits under a contract of employment or collective agreement, the benefits are comparable to those under a private insurance policy and no deductions should be made for such benefits from the award for lost wages. Cory J. explained the policy rationale for the rule regarding non-deductibility of collateral benefits at 400-1: I think the exemption for the private policy of insurance should be maintained. It has a long history. It is understood and accepted. There has never been any confusion as to when it should be applied. More importantly it is based on fairness. All who insure themselves for disability benefits are displaying wisdom and forethought in making provision for the continuation of some income in case of disabling injury or illness. The acquisition of the policy has social benefits for those insured, their dependants and indeed their community. It represents forbearance and self-denial on the part of the purchaser of the policy to provide for contingencies. The individual may never make a claim on the policy and the premiums paid may be a total loss. Yet the policy provides security. Recovery in tort is dependant on the plaintiff establishing injury and loss resulting from an act of misfeasance or nonfeasance on the part of the defendant, the tortfeasor. I can see no reason why a tortfeasor should benefit from the sacrifices made by a plaintiff in obtaining an insurance policy to provide for lost wages. Tort recovery is based on some wrongdoing. It makes little sense for a wrongdoer to benefit from the private act of forethought and sacrifice of the plaintiff.