When I work the gate here in YYJ there is almost always one or two people that think they are on the 14:00 flight when they are actually on the 15:00 (for example). As we don't have scanners here, I just make sure I double check it is the correct flight number and do a double check that the names do match. That being said, we are still human and mistakes do happen (just like you sometimes give the agent the wrong boarding card).