What is the test for elected trial by judge without a jury?

The leading authority is Matheson v. The Queen (1981) 1981 CanLII 202 (SCC), 59 C.C.C. (2d) 289. In that case the accused was charged with robbery and using a firearm while committing an indictable offence. He elected trial by judge without a jury. During the preliminary hearing on the first charge the accused re-elected trial by magistrate, entered a plea of not guilty and the court proceeded to hear the rest of the evidence. The evidence adduced at the trial on the first count was then read into the record on the second count and the accused was found guilty of both. The evidence heard at the preliminary inquiry preceding the re-election and trial was never read into the record.