The principles applicable when there is an allegation of unreasonable verdict are summarized in R. v. R.P., 2012 SCC 22 (CanLII), 2012 SCC 22,  1 S.C.R. 746. Deschamps J., for the majority wrote:
 To decide whether a verdict is unreasonable, an appellate court must, as this Court held in R. v. Yebes, 1987 CanLII 17 (SCC),  2 S.C.R. 168, and R. v. Biniaris, 2000 SCC 15 (CanLII), 2000 SCC 15,  1 S.C.R. 381, at para. 36, determine whether the verdict is one that a properly instructed jury or a judge could reasonably have rendered. The appellate court may also find a verdict unreasonable if the trial judge has drawn an inference or made a finding of fact essential to the verdict that (1) is plainly contradicted by the evidence relied on by the trial judge in support of that inference or finding, or (2) is shown to be incompatible with evidence that has not otherwise been contradicted or rejected by the trial judge (R. v. Sinclair,2011 SCC 40 (CanLII), 2011 SCC 40,  3 S.C.R. 3, at paras. 4, 16 and 19-21; R. v. Beaudry, 2007 SCC 5 (CanLII), 2007 SCC 5,  1 S.C.R. 190).