What is the legal test for admitting fresh evidence on appeal concerning matters that pre-date the trial?

The admission of fresh evidence on appeal concerning matters that pre-date the trial is a discretionary matter, determined in accordance with a more flexible application of the traditional criteria applicable to the admission of fresh evidence articulated in Palmer v. The Queen, 1979 CanLII 8 (SCC), [1980] 1 S.C.R. 759, at p. 775: 1. The evidence should generally not be admitted if, by due diligence, it could have been adduced at trial. 2. The evidence must be relevant in the sense that it bears upon a decisive or potentially decisive issue in the trial. 3. The evidence must be credible in the sense that it is reasonably capable of belief. 4. The evidence must be such that if believed it could reasonably, when taken with the other evidence adduced at trial, been expected to have affected the result.