A good starting point for anyone seeking to gain an appreciation of the role of the trial judge in the Canadian criminal justice system is the following passage from the Honourable Justice Jamie W.S. Saunders of the Nova Scotia Court of Appeal in R. v. Al-Rawi,  N.S.J. No. 18, beginning at para. 126:
…a judge's work is conducted in public view, as required by our open courts principle, where virtually every word is transcribed, and becomes part of the public record. As well, judges swear an oath to decide the matters that come before them independently and impartially, without fear or favour, and thereby render justice according to law.
A judge's duties always involve the resolute application of a host of fundamental principles that include the Rule of Law, the presumption of innocence, the Crown's never-shifting burden to prove all essential elements of the offence beyond a reasonable doubt, and the obligation to provide reasons to explain the verdict. It is well accepted that a judge "speaks" only through his or her decision, and is prohibited from later offering further commentary to clarify or add to those reasons.
Sitting on appeal, we require trial judges to make strong findings of fact, decide matters of credibility, apply the law to the evidence correctly, and express themselves in plain, unambiguous language. That is the law, which is there to protect the rights of any citizen whose actions form the basis of a criminal prosecution. And those are obligations that apply to every kind of case, so that when matters are appealed, the record from the court below will provide a proper basis for meaningful appeal.
If it is shown that the trial judge erred, to the extent where appellate intervention is warranted, the appeal will be allowed, the judgement set aside, and a suitable remedy granted. Those are the "checks and balances" our system of justice provides. …