When Tiffany and Dennis are attacked by the killer Santa Claus, the killer appears from behind the open bathroom door that was nearly closed in the shot before. This means that the killer had to open the door, walk into the room and hide behind the door without Tiffany and Dennis noticing him. This is unrealistic since Tiffany is lying on the bed in front of that door and Dennis is also looking in the direction of the door during the entire scene.
When Sheriff Cooper and Deputy Bradimore are talking in front of the blackboard, the word "Karsson" keeps changing continuously to Karson with only one S and back, and the line underneath the word changes, disappears and returns.
In the final fighting scene between Deputy Bradimore and the Santa, Bradimore's hair changes from being tied up to the hair being loose in between scenes.
When Tiffany sees the killer walk up the stair to the Motel photo-shoot, she is stood by her drivers side door; the window is down, in the next shot, the drivers side window is all the way up.
When husband burns his cheating wife, she is shown burning, but her mouth is closed and she acts like she is feeling no pain at all.
The name of the town is Cryer but the name on the water tower shows the end of Selkirk, the town where it was filmed.