Possible, yes, but he'll need to rush. AC's minimum connection time for AC-AC within terminal 1 for US-Canada is 60 minutes, and that only involves a cursory stop at customs and you don't need to re-clear security. I don't know what MCT is in your friend's situation, but he will need to clear (full) customs, switch terminals (and not get lost) and re-clear security. I assume it is a legal connections since he was able to book on a single ticket. Hopefully the inbound isn't late.