Factual error: When Max goes to the bait shop with John and they are talking to Chuck about him going over to Ariel's house for Thanksgiving, they ask him if he saw the Blackhawks game, saying that it went into double overtime. NHL games only have one overtime unless it is a playoff game.
Revealing mistake: In the scene where Max is trying to find the source of the bad smell in his car, a shot from behind shows a view out the windshield. The column shifter is in Park even though Max is driving.
Visible crew/equipment: In the VHS edition, one can see a reflection of a boom mic in the painting above the staircase landing as Ann-Margaret goes up the stairs to Jack Lemmon's bathroom, and again when she comes down.
Continuity mistake: When the snow falls from the roof onto the IRS agent, he falls down and rolls forward, and almost all of the snow lands several feet behind him. When the shot changes to a side view, he is now closer to the house again, directly under the snowfall.