Factual error: After Robert De Niro awakens, Robin Williams takes him on a ride around New York and Robert is amazed by all the surroundings. The movie is set in the early 1970s, but you can see plenty of vehicles around from the time that the movie was filmed (1990). Notice the square headlights that originally appeared in the late 70's.
Continuity mistake: Dabney Coleman and the villain fight on the scaffolding on the side of a skyscraper high above the city. They are the only two people on the scaffold, but during the fight at the bottom of the screen you can clearly see a man's head.
Continuity mistake: In the scene where Barney is headed home from work right before his wife leaves him for the athlete, the sun looks like it's morning sun. After about 30-45 seconds into the conversation with his wife why she is leaving, the sun changes to a late afternoon. It is very apparent on the mailbox. The shadows completely change direction in a matter of minutes. (00:08:20)
Factual error: When the Security Guard in the pump room gets bitten on the nose, he starts shooting with his revolver (a SIX shooter). Count the bangs. He manages to fire SEVEN times. (00:39:45)
Continuity mistake: When Jimmy goes into the big house, he does not close the door, but while he is dancing you can see behind him the door open/close/open.
Continuity mistake: When Troy and Rowsdower are standing and looking up at the Lost City that flies up and leaves the planet it is dark. But a few seconds later, while they are still looking upwards towards the city, it is full daylight.
Revealing mistake: During the pirate attack, Rosencrantz sits up in bed, narrowly avoiding a sword that's thrust through the wall next to him. Just before the sword appears, the film jumps a little. It also jumps again just after the sword has been withdrawn and he lies back down. Clearly these two motions (him sitting up and down in bed and the sword appearing/disappearing) are two separate takes that were spliced together.
Continuity mistake: When DeDe walks into Joe's apartment at the end of their date, she places her handbag on the floor a few steps across from the door. When she comes back in to get the bag because she forgot it after she leaves, she reaches for the bag just inside the door.
Continuity mistake: As the guys sit down for a beer and start talking, the viewing angle is from behind the one listening. As they switch to the other one who's about to say something the two bottles of beer magically turn around so you can always read the front label, no matter from which side the scene is shot.
Revealing mistake: In the beginning, when Hamlet's father is being buried, the new king takes his sword and places it down onto the grave. When he does this, the tip hits first and you can see the blade bend.
Continuity mistake: About 20 minutes into the film Gene Hackman and his witness drives a big 4x4 through the mountains of British Colombia, trying to evade being shot at by gunmen in a helicopter. While they are being shot at, the windshield gets smashed, and is in pieces. The following scenes show the windshield intact one minute and smashed the next.
Visible crew/equipment: When the lizard gets away, and is riding in the elevator, it is shown alone in there. In the next shot from the back of the lizard, you can see the shadow of the handler or crew-member's head moving around on the top of the lizard.
Visible crew/equipment: When Joey is showing one man a red car, when the man opens the car door to get in, a large white reflector screen and a crewmember holding it are reflected. (00:31:00)
Continuity mistake: When Lily breaks into Roy's apartment, she unscrews two small light bulbs in the fixture next to the front door, throwing that whole end of the hallway into darkness. When Roy returns home, he opens the door and the hallway is brightly lit again. (01:32:45 - 01:34:15)
Visible crew/equipment: When Nimbly takes off and flies onto Xayide's wagon, the wires pulling him up are visible. (00:58:35)
Revealing mistake: When Graham and Stella are in bed, the camera shows only their arms intertwined as if he's lying on top of her. She's gasping loudly in response to his thrusting, but their arms never move back and forth to reflect this, so it's clear they're not really having sex.
Continuity mistake: When Maria is cleaning up the water on the floor, the rag is red in one shot and then blue in the next.
Audio problem: In the scene where Kid N Play are freestyle battling, you hear mixing in the background. But Bilal is not mixing, but in fact watching Kid N Play.
Continuity mistake: When Ralph is running from the hunters at the end and he finds the pig's head on the stick, he stops with his arms spread out a bit. In the next shot, even though you only see his head and shoulders, you can tell that his arms are now straight at his sides.
Continuity mistake: When MSgt McKinny is patting down the prisoners for contraband, his cap changes position on his head between shots. (00:34:55)