Other mistake: When Jack first arrives in Christmas Land he doesn't know what is falling from the sky (snow) but he somehow knows that the children are throwing snowballs.
Continuity mistake: One of the tiles comes loose when Wallace is walking across the ceiling in the museum. A few seconds later, the tile is flat against the wall again.
Audio problem: After Batman has left Andrea's apartment she drops a glass. We hear the sound of the glass shattering, but when the camera zooms out we see the glass is still in one piece.
Continuity mistake: When Bob tells Junior that Larry is a cucumber, the carpet and the shadow of Junior's bed shift to the right a little bit.