Continuity mistake: Early in the movie, there is a black clock on the wall in Dan's kitchen that reads 7:50. Later, when he is in Alex's apartment strangling her, the same black clock is now in her apartment and it, too, reads 7:50.
Continuity mistake: At the end Michael Douglas is standing in front of his home with the door open in the background with the hallway illuminated. The camera angle now switches to inside the house, but he has to enter the house through a closed door.
Continuity mistake: When Dan throws Alex into the bath, she goes in face down, but suddenly she is face up - which would be a difficult manoeuvre in a small bath.
Continuity mistake: When Alex, naked in bed, jumps up to stop Dan leaving, she attacks his shirt, and you can hear it ripping, but, later, it's completely fine - no ripped bits anywhere.
Continuity mistake: When Dan leaves the budget office in his rental car, the front license plate is mounted off to one side, unusual for this type of vehicle. When he arrives at the house, it's still the same license plate number, but the plate is now mounted on the centre of the bumper.
Continuity mistake: When Dan's wife is by the dinner table talking about the house, his arm is up, yet a frame later from a different angle is down.
Continuity mistake: After Alex and Dan go dancing and go back to her apartment, she reaches up to get a door key from the top of an electrical box outside her door. She takes down the key in her right hand and then opens the door with her left hand. The key never goes near the lock or doorknob.
Continuity mistake: Michael Douglas is going home to Mount Kisco the very very long way down Riverside Drive South. Again Alex's tape hasn't skipped a beat.
Continuity mistake: In the scene where Beth is desperately trying to find Ellen, she approaches a stopped Chevrolet Caprice wagon and rear ends it. When the camera switches to an interior shot of Beth's vehicle during the collision, the vehicle in front has changed to a Ford LTD wagon.
Continuity mistake: While eating together, Alex tells Dan that she stood up her date, and raises her hand. From the opposite angle it's lowered.
Continuity mistake: When Dan and Alex are under the rain, a black man in a gabardine passes by Dan, and a frame later passes by Alex, in the opposite direction.
Continuity mistake: Dan is having a drink with Alex and he talks about his parents' divorce. His glass swaps from being on the table to in his hand between shots.
Continuity mistake: When Glenn Close calls Michael Douglas in the middle of the night, his clock radio reads 2:13. In the next shot, without him touching it, the clock is dimmer and has been moved so we can't see the new time. Then about a minute later, the clock radio reads 2:20.
Continuity mistake: Dan throws his umbrella and it bounces on the edge of the wastebasket but lands on the floor. When he walks next to the wastebasket the umbrella is now inside.
Suggested correction: It lands on the ground and stays there.
Continuity mistake: When the phone rings as Beth paints, Beth puts her roller in the tray and goes to answer the phone. When she returns the roller is in a different position than it was before.
Continuity mistake: When Michael Douglas puts on his headphones to listen to the tape in his den, he puts the headphone with the cord on his left ear. When his wife startles him the cord is on his right ear.
