Continuity mistake: At the Policeperson's Dance, Copeland spills punch over the Commissioner's wife's white dress. As the camera view switches, her dress is already stained before she is splashed.
Revealing mistake: When Frank is knocked down with the tray, the arms of the person operating Johnny 5 are visible when the robot turns to run.
Continuity mistake: Notice the candle on the table in the Italian restaurant scene during Capt. Kirk and Dr. Gillian dialog. It changes height depending who is talking. (01:03:50 - 01:08:30)
Visible crew/equipment: After the gardening tools attack Roger in the shed, when Roger loads the shotgun to confront the marlin mounted on the wall, just as he enters the room and stops, the boom operator's raised arm is visible on the left side of the screen. (00:43:45)
Continuity mistake: At the beginning when the helicopter lands, the helicopter's shadow goes out toward the rear right of it (from the pilot's perspective), but when Sue grabs her bags and walks to Walter, the shadow is now cast to the front right. Since Sue got out and was standing next to it, the helicopter did not move in the meantime. (00:03:15)
Visible crew/equipment: The two protagonists cash in the win and are running from the goons who chase them. The car of the two baddies is parked outside. During the sequence when the car loses the second door, you can see reflected with great detail the camera crew and stage lights, right in the side of the car. (00:26:50)
Revealing mistake: When the microlight is about to fall into the lake next to the lab, Howard's POV shows a straight road ahead. However, a shot later the microlight rises from an obvious ramp hidden between bushes which results in a more comedic crash.
Continuity mistake: In the scene where he is fixing breakfast for his daughter, Robert Redford's shirt sleeves are down. When he goes to rescue the burning toast in the oven, his shirt sleeves are up and then they are down again. (00:15:00)
Continuity mistake: When Jack Burton and the rest of the gang escape from the Wing Kong Trade Centre the first time, the guards fire at the left side of the bus breaking the windows and making holes in the bodywork. When we see the bus a few seconds later as it is driving away, it appears undamaged.
Continuity mistake: When Rooney gets on the school bus, he crosses a grass boulevard with no sidewalk to board it. The bus never moves. When the bus pulls away, there is a sidewalk next to the bus where the grass was.
Continuity mistake: When Tommy Tong breaks Jarrel's stick, the broken part of the stick differs between shots. (00:33:40)
Revealing mistake: The chairman parks his car in front of Bel Fuse Ltd. And goes upstairs. His car explodes, but does it in front of a different building, probably switching to a stage building front; the metal doors don't have vents anymore and there are visible join lines in the asphalt and the cement. (00:15:10 - 00:15:40)