The plaintiff in Demers v. B.R. Davidson Mining & Development Ltd.  ONSC 2046 received CPP benefits following a car accident in 1999. A dispute arose as to the deductibility of these benefits.
Prior to November 1, 1996 it was clear that CPP benefits were not deductible. The law in this respect became less clear with the enactment of Bill 59. This Bill dealt with car accidents occurring after November 1, 1996 and before October 1, 2003. As a result of its enactment, s.267.8(1) of the Act provided for the deduction of benefits for “loss of earning capacity”. What wasn’t clear was whether this included CPP benefits.
To complicate matters further, there were two conflicting court decisions. The court in Meloche v. McKenzie , O.J. No. 3761 (S.C.J.) looked to the 2003 amendments which specify that CPP benefits are deductible and concluded that this amendment must be a clarification of the original legislation. The court in Sonnenberger v. Creamer,  O.J. No. 754 (S.C.J.) made the opposite finding as it took the position that the amendment did not provide for retrospective application.
There is also a Court of Appeal decision, Kosanovic v. Wawanesa Mutual Insurance Co.,  O.R. (3d) 161 (C.A.) which held that CPP benefits were not deductible for this time period. This case was not considered by the court in Meloche and arguments were made by the defendants in Demers that this case should not be considered.
Shaw J. found Kosanovic relevant and binding but also focused on two principals of statutory interpretation to settle the issue: 1) the ordinary meaning of a legislative provision should prevail absent a good reason to reject it; and 2) there must be something in the wording of the provision or in the circumstances in which it is enacted to indicate that the provision is meant to be retroactive. He concluded that the legislation in effect in 1999, when the accident occurred, does not expressly provide for the deduction of CPP benefits and the amended legislation does not indicate retroactivity.
As a result of this case there appears to be two distinct periods of time: 1) accidents which occurred between October 23, 1989 and September 30, 2003 (CPP benefits not deductible); and 2) accidents which occurred after October 1, 2003 (CPP benefits deductible).