I imagine that the perception might be that a judge will approach the case more rationally and technically, whereas the jury might be swayed by sympathy for the victim, biases, etc. To what extent that's true I do not know, but conviction rates are significantly lower in Canada than in the U.S.
Maybe he or his lawyers thought he would fare better with a judge? Hard to say. I've heard that there are a lot fewer jury trial in Canada vs US but I'm not sure why.
Why?