Continuity mistake: When the TV repairman shows up to find out what's wrong with the TV for the last time she says that she found out the problem with the TV: "this shoe." It was a shoe that was left in the TV after Michael Keaton kicked the screen in. However, watch the scene, his shoe never leaves his foot.
Continuity mistake: When Carolyn leaves the house for her first day of work the sun is out, then it begins thundering and raining. It's pouring while Jack takes the kids to school. When Carolyn gets to work, the camera shows a far back shot of her new office building and the streets and all are clearly dry - she could work in a different part of town, but then when she gets in the elevator, which is made of glass and on the outside of the building, it's soaking wet from the rain.
Continuity mistake: When Martin Mull and Teri Garr fly to the West coast on the company's private jet they have a bottle of champagne. There are three shots: both of them, him, and her. During the cutting between shots the ice in the champagne holder keeps disappearing and re-appearing throughout the scene.
Continuity mistake: When Larry is tossed back into the chair, he points at the boss, asking why his firing wasn't told earlier. After the angle cut, both hands are on the arm rests.