R. v. Laing, 2016 ONCA 184:
 The leading case on the failure to preserve evidence is R. v. La,  2 S.C.R. 680, the principles of which are summarized in R. v. Bero (2000), 151 C.C.C. (3d) 545, 39 C.R. (5th) 291 (Ont. C.A.), at para 30. For present purposes, the key consideration is whether the DVD was lost as a result of what Justice Sopinka termed "unacceptable negligence".
 The trial judge concluded that in order to establish that the standard of unacceptable negligence had been met, the conduct of the police would have to be such as to shock the conscience of the average citizen.
 That was a mistake. Conduct that shocks the conscience of the average citizen is relevant to determining whether a failure to meet the disclosure obligation constitutes an abuse of process, but it is not necessary to find such conduct in order to establish "unacceptable negligence". As Justice Sopinka stated in La, a failure of disclosure "may also suggest that an abuse of process has occurred, but that is a separate question. It is not necessary that an accused establish abuse of process for the Crown to have failed to meet its s. 7 obligation to disclose": at para. 20.
Of the Law Societies of Upper Canada and Nunavut