Continuity mistake: When Michael Douglas is listening to a "deposition" (which is really Glenn Close calling him names, etc.) using his ear phones in his new attic home (just before his wife comes up and finds him), the audio tape is not the same one as he was listening to minutes before in the car! The words are almost the same but the inflections are different.
Suggested correction: It is the same tape, although a mistake does remain - the tape when first being played in the attic is a few sentences before where the tape should start (without him rewinding it at all).
Revealing mistake: In the final confrontation scene Glenn Close comes out of the bath tub and raises her arm, the scene cuts to the gun and when it returns to Glenn Close you can see the fabric of her dress has changed to a thicker one to accommodate and cover the squib needed for her gunshot wound. (01:54:05)
Visible crew/equipment: In the library, right after Dan breaks into Alex's apartment, a cameraman's reflection is visible in a window as a librarian pushes a cart past it.
Continuity mistake: The amount of blood on Dan's face, when Alex slits her wrist, keeps changing.
Visible crew/equipment: In the beginning of the movie as Michael Douglas runs to answer the phone someone has knocked the overhead lamp in his kitchen and set it swinging. (00:03:05)
Continuity mistake: The water level was almost but not quite overflowing the brim of the tub when Michael Douglas is pushed in, and the faucet was still running, so there should have been more water on the floor. (01:52:25)
Continuity mistake: There is a lot less blood on the knife after Glenn Close flings it than there was in the shot before when you see her fall. (01:51:50)
Continuity mistake: Fred Gwynne's pipe jumps from his hand to his mouth when he and Michael Douglas walk up the stairs to his office.
Visible crew/equipment: The shadow of a crew member goes across Michael Douglas' shirt as he's sitting on the couch reading in the beginning of the movie. (00:02:25)
Continuity mistake: The amount of wine in the Michael Douglas' glass changes in the scene where he is talking to his daughter about rabbits. It fills up without being touched. (00:41:30)
Continuity mistake: (DVD only) In the new ending, when Alex attacks Beth at the family's home, Beth has bruises and a cast on her arm, obviously a result of the accident she was in a few days ago. In the original ending, presumably taking place within the same time frame, when the cops come to question Dan about Alex's death, Beth is fine - no bruises, no cast, she doesn't even look tired.
Continuity mistake: In the scene in the tub, Glen Close's feet start out filthy, then they become clean as a whistle when she is flailing from her knees, then by the end of the scene they're disgusting again. (01:52:40)
Other mistake: Dan and Alex go to what looks to be Alex's apartment after meeting at the office and going for a drink. After romping around in bed, they go dancing, and on the way back through the meat-packing district, she leads him to the door of her apartment and tells him she lives upstairs and he says something like, "this is your building?" It seems odd as they were just up there having sex.
Continuity mistake: When Alex goes to see Dan in his office, Dan in the first scene is sitting with uncrossed legs, then his legs are crossed, then uncrossed again.
Revealing mistake: When Michael Douglas is listening to the "deposition" in his study, look closely at the background window. You can see Anne Archer's reflection in the glass, together with someone else (probably crew), just waiting for her cue to come in and surprise her husband.
Continuity mistake: Dan throws his umbrella and it lands on the pavement. In the following shot it's in the wastebasket.
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.
Revealing mistake: Inside Alex's apartment when the stunt double breaks the glass, you see by the way it breaks that it is untempered glass. This first mess is cleaned up and then they put down other stuff that looks tempered but isn't real glass at all. (01:42:00)
Continuity mistake: As a little girl is sitting on the couch with the dog, there is a book to the left of her which is gone in the next shot. (00:02:35)
Continuity mistake: As Michael Douglas listens to the answering machine, the green overhead lamp that is above the table in the beginning of the movie is gone. (00:22:20)
