R v O’Connor – (1995) 4 SCR 411 (McLachlin):

[193] The task before us on this appeal is to devise a test for the production of records held by third parties which preserves the right of an accused to a fair trial while respecting individual and public interest in privacy and the efficient administration of justice. The key to achieving this lies in recognition that the Canadian Charter of Rights and Freedoms guarantees not the fairest of all possible trials, but rather a trial which is fundamentally fair: R. v. Harrer, [1995] 3 S.C.R. 562. What constitutes a fair trial takes into account not only the perspective of the accused, but the practical limits of the system of justice and the lawful interests of others involved in the process, like complainants and the agencies which assist them in dealing with the trauma they may have suffered. Perfection in justice is as chimeric as perfection in any other social agency. What the law demands is not perfect justice, but fundamentally fair justice.