"As a matter of fundamental principle, a statute is not to be construed as having a retrospective operation unless such a construction is made evident by its terms or arises by necessary implication. However, the presumption against retrospective construction has no application to enactments which relate only to procedural or evidentiary matters. "
R. v. Bickford  O.J. No. 835, 1989 CarswellOnt 990 (C.A.) at para. 11.