Alej24601

Visible crew/equipment: Just before Clark goes down the hill on the saucer sled you see the view down the hill. If you look carefully at the right of the screen you can see two pinkish cables stretch into the distance. These are the pyrotechnics that make the explosions Clark sets off. You can see it clearly on the DVD version, but not too clearly in the VHS one. (00:50:15)

Continuity mistake: When Clarke is installing the Christmas lights, the rope on the ladder keeps appearing and disappearing. (00:23:00)

Dr Wilson

Revealing mistake: When Clark and Ellen are in the bed and Clark's hands are sticky, you can see that he actually grabs her hair to give the illusion that they are stuck, and he turns one of the pages of the magazine just fine. (00:12:30)

Continuity mistake: When Todd, the snob neighbor, falls down the stairs, his wife Margot is not visible in the bedroom. (00:38:55)

Dr Wilson

Continuity mistake: When Clark is outside hanging the lights, he staples the sleeve of his shirt, under his wrist, to the eaves of the house. In the next shot, as he is pulling, the shirt is stapled over his wrist. (00:21:50)

Continuity mistake: When Clark is going crazy, he cuts the newel post. But it's still in place in the later scene, when the family has problems with the squirrel. (01:18:15 - 01:21:20)

Continuity mistake: The blinds are ripped out of the neighbors' window frame when Clark "harvests" his replacement tree from outside. However, when Margot is outside telling Todd to "slug that creep in the face", you can see blinds are still in the window. (01:17:20 - 01:21:55)

Character mistake: Clark has too many lights on his house causing the city to go dark. There is a scene where the power plant needs to boost their output. There is a close-up of a guy flipping the switch. Look at the way they spelled auxiliary - auxilliary. (00:37:54)

JamesP

Revealing mistake: When Uncle Louis drops the match in front of where Eddie empties the "chemical toilet" if you look VERY close you can see the rope that launches him into the air. (01:32:05)

Continuity mistake: When the Griswolds are driving to the tree farm, they are being harassed by the rednecks in the truck. Several shots of the front of the truck show only two passengers, but one view of the truck through its rear window shows three passengers. (00:04:17)

Factual error: In the montage sequence showing Drew Barrymore hanging out with the math club, they have a Pi poster with 3.1457869986. Only the first 3 digits are actually correct. (Pi = 3.1415926535897...) (00:25:20)