Revealing mistake: The Asian man at the airport terminal is struggling very hard not to laugh at Jim Carrey's antics, as seen from his reflection in the glass.
Other mistake: When Lloyd gear shifts the limousine at the airport he only moves it down one notch, which would be reverse. The limo still moves forward.
Plot hole: By the time Lloyd gets to the airbridge the plane had already left. The finalisation of the boarding process after last call, plus push back takes at least 15 minutes. Lloyd would have easily caught up to Mary or the plane would have still been there.
Continuity mistake: At the snow owl benefit, Helen raises her hand as Nicholas is introducing Carl. In the next shot which is the opposite angle, her hand is down, and she repeats the action, but with a drink in her hand.
Continuity mistake: During the snowball fight scene at the ski resort, it's either snowing or not depending on the angle. In one shot it's sunny. The first two shots showing just Harry feature snow. Cut to Mary and it's not snowing.
