Other: In the scene where Walther Matthau is making sandwiches for his poker pals (during the movie's first poker game), Matthau drops a loaf of bread on the kitchen floor. If you look at his hand, you'll see that he flicks his thumb to make the loaf of bread fall.

Continuity: When Felix enters the Flanders Hotel at the beginning and asks for a higher room, the man behind the counter puts his pizza on the counter, but in the next shot, it's in his hand again.