Continuity mistake: At the end of the movie, when Clark is outside of the house with Eddie's dog, all the police cars have disappeared. (01:34:10 - 01:35:00)
Suggested correction: It's the end of the movie with credits rolling, I would think the people behind the movie wanted it that way with Clark looking proudly of his Christmas night. his last line in the movie, he said "I did it" and the lights went off on the "THE END" sign. So, that's what I think about the ending. It's not a mistake. It would be if the sign wasn't shut off and started rolling credits after he said his line and nothing's there.
Continuity mistake: The christmas tree is visible from the dining room, but when Lewis goes beside it to smoke a cigar, you can't see him. When the tree is on fire, you don't see Lewis again and you can only see a branch of the tree.
Continuity mistake: When the squirrel jumps out of the tree and the whole family is hiding around the corner in the front entry, the camera alternates shots frequently from the front of the family to the back of the family. Each time the angle changes, Catherine's stance changes from her arm being around Russ to her arm at her side.
Continuity mistake: Less than a day after the ice breaks the neighbors' window, it has fixed itself in the outside shots as Clark is stuck in the attic.
Continuity mistake: When Clarke is installing the Christmas lights, the rope on the ladder keeps appearing and disappearing. (00:23:00)
Continuity mistake: When the squirrel is being chased by Eddie's dog, it passes through the broken door and then vanishes. (01:22:07)
Continuity mistake: As the shots quickly change from the front of Catherine and Rusty to their backs, Catherine is either holding Rusty tightly to her, loosely, or not at all.
Continuity mistake: When Clark falls off the roof, the staple gun goes down before him. In the next shot, it's not heading down from his point of view.
Continuity mistake: As Clark is stapling the Christmas lights to the house, there are bits of snow and ice on his left-hand glove in the close-ups. But in the longer shots of Clark, the glove has no snow and ice present.
Continuity mistake: After Clark dedicates the Griswold Family Christmas tree and it expands, Ellen's hands are on her hips, but the next quick shot of her shows her hands clasped behind her back.
Continuity mistake: After Clark cuts the rope restraining the tree branches, Rusty is very close to the tree, but the final shot when Clark gives the "OK" sign shows Rusty about two feet from the branches.
Continuity mistake: When they first step up to the tree in the forest, Audrey is still moving. In the overhead shot, she stops, and we can see tracks in the snow where all four have been standing. The problem is, there are a lot of tracks. We're lead to believe they just walked up to the tree.
Continuity mistake: In the scene of Clark standing in the snow trying to figure out why his Christmas lights did not work, the paper he is holding in his right hand is mid torso to him, but in the next shot when Rusty leaves him, his right hand has instantly dropped to his side and he raises his paper-holding hand again.
Continuity mistake: When Clark, Eddie, and Catherine are admiring the Christmas lights of the Griswold house, Clark is very close to Eddie with his left arm draped over Eddie's shoulder, but the next quick cut to Clark when he says, "Eddie?", shows Clark further away and his left arm at his side, and not stretched out.
Continuity mistake: In the Christmas dinner scene, closeups of Rocky show his right hand raised to his face, but the overhead shots do not.
Continuity mistake: After Mr. Shirley tells Clark he will get a bonus plus twenty percent, Catherine, Rocky, and Ruby Sue cheer and get up from the couch to mingle with the relatives while Rusty and Audrey respond excitedly. There is a close up reaction shot of Clark as he begins falling, then a long shot of Clark falling to the floor as Catherine, Rocky, Ruby Sue, Audrey and Rusty are in their original positions on the couch, calmly watching Clark fall.
Continuity mistake: After the tree burns, Rusty says, "Dad's gonna flip out." Clark Sr.'s left elbow is close to and behind Rusty's head, but in the next instant shot of Rusty, Ellen, and Audrey, Clark Sr.'s elbow is not there.
Continuity mistake: The retractable attic staircase is a type held closed only by light spring pressure, not a latch, but it doesn't budge when Clark jumps on it. When he initially opened it, and later when his wife does the same, it opens normally with a light tug from below on the cord.
Continuity mistake: When Todd, the snob neighbor, falls down the stairs, his wife Margot is not visible in the bedroom. (00:38:55)
Continuity mistake: When the family is on the front lawn to inaugurate the Christmas lights, between shots a blue Lincoln at the curb disappears and a station wagon appears across the street.