Yes. His luggage will be checked through to its final destination. All he has to do is walk out and he's free as a bird - just needs to be back in time to clear security and walk to the gate - get back to airport 45 mins to 1 hour before departure of YYZ-AMS should be fine.

(If he has a bunch of carry-on, there is also a luggage store where he could store the stuff for a small fee for the few hours he is away - http://www.cntower.ca/site_Files/Con...age_Info2S.PDF ).