What is the test for an appeal court in considering an allegation of error on the face of the record?

In Bond v. McKenzie, supra, Lambert J.A. set out what confronts a reviewing court in considering an allegation of error on the face of the record. After pointing out the onus rests on an appellant (unless the statute says otherwise) to demonstrate that there has been an error, he noted at ¶20-22: ...It is not sufficient to show ambiguity or possible error. To act an appeal court must conclude that the lower court has fallen into error. Errors of law and of fact are readily discernable where the lower court or tribunal provides reasons. It is only where the lower court or tribunal fails to set out the law, or facts, or reasons for its actions that difficulty can arise. Unless a statute requires a court or administrative body to prepare Reasons for Judgment, it is not normally error of law to fail to do so. Where no reasons are prepared, or the reasons are silent on a point in issue, the reviewing court must find a rational basis for concluding that the lower court (or administrative body) erred in appreciation of a relevant issue or in appreciation of evidence that could effect correctness of the verdict or decision.