Continuity mistake: When Cameron Diaz and Jude Law are in bed for the last time, her bra strap changes from being up and hanging down whenever the camera changes.
Continuity mistake: The first movie shows Santa slipping on the roof and kicking up a white snow blanket as he falls. The flashback in the third movie does not show the blanket being kicked up as Santa slips.
Continuity mistake: When Steve Finch crosses the street to talk to Buddy Hall outside the hardware store, he raises his collar around his neck. Slightly further on in the scene, when the two are in front of the tree, he places his hands in his pockets. The two then walk back to Hall's pickup, at which point Finch's collar is down, and returns to being up when they finish walking. At no time does Finch remove his hands from his pockets.
Continuity mistake: At the end, while Billy chases Kelli, Kelli knocks over a cart of surgery supplies, spilling the material forward. However, a few shots later, Billy is shown picking a scalpel up from the small tin pale, which slid ahead of Kelli. So how could Billy have picked up the scalpel if he was behind Kelli?