Other mistake: When the lights don't work, Clark punches Santa and knocks the antlers off the reindeer. When the lights come on and the family comes out, the antlers are back on their heads.
Continuity mistake: When the grandfather is sleeping in the top of the bunk bed, there's a cheesecake poster on the ceiling. When Clark falls through the attic floor onto the bunk bed, it's not there.
Continuity mistake: The first time Clark fails with the lights, Ellen's mother says she hopes the kids see what a waste of resources it is. During this scene the level of her martini changes.
Continuity mistake: When Clark is looking at his "bonus check", he's holding both the envelope and "check" together in both hands. In the next shot he's only holding the "check" in both hands and the envelope is no longer under it.
Continuity mistake: When Clark falls over while on the ladder, after ripping his sleeve off, his hands keep changing position on the ladder. When he first starts to fall, his right hand is gripping the side and in the next shot both hands are gripping the rung. In the next shot both hands are on the side of the ladder until the shot after he pushes himself away from the tree and they go back to being on the rung for a shot.
Continuity mistake: When Clark is talking to the pretty saleswoman and she says "well, you do have your coat on", he tilts his head down and to his right. In the next shot his head is to his left and he moves it to the right.
Revealing mistake: When the SWAT team arrive at the house, a member of the team runs towards the house and dives in the snow. However, instead of falling in the snow as you would expect, the white fabric on the floor bunches up.
Revealing mistake: When Clark (on the saucer sled) reaches the bottom of the snow hill, and is on the highway, as the headlights of the truck are coming at him and the "sparks" are flying from under the sled you can see the wheels underneath to make it roll across the highway to reach Walmart's parking lot.
Continuity mistake: The entire Christmas bonus scene at end, Clark's tie changes. Take note of the pattern on the knot, which changes from shot to shot.
Continuity mistake: When Santa Clause's sled passes in front of the moon at the end, why is the sea so dark? It wasn't in previous shots.
