Does he actually have two different colored eyes, or is that just the lighting?
Pugs can be sneaky little bastards though... My uncle's had 2 or 3 of them at any given time over the last 2 decades or so, and he was sitting down to a barbecued steak dinner one night. Pug starts barking his head off and looking in the general direction of the front door, so my uncle gets up to see who's at the door, and the minute he leaves, dog jumps up on his chair, grabs the steak in his mouth and runs like Hell!