Revealing mistake: During the sequence with the Native Americans chasing the Delorean in the beginning, in one shot looking up at the sky you can see contrails from a plane, obviously not around in 1885. (00:19:25)
Continuity mistake: The books and other items on the desk of the boy sitting behind Andy move about between shots, and the boys sleeves change from rolled up his arms to pulled down to the wrists too. (00:33:00)
Continuity mistake: Bruce Willis is emerging from an underground air-vent when the plane with General Esperanza is landing. Initially the plane is coming on a direct course for him and he struggles to get out. In fact the front wheel is on course with and knocks the vent cover. But in the very next scene, the tire marks clearly show the front wheel passed to the right of the vent and so completely missed it. (01:11:40)
Visible crew/equipment: When Splinter throws Shredder over the wall, Splinter's puppeteer is visible. (Full screen only).
Continuity mistake: When Doug is running from the bad guys after finding out what was going on from his "wife", he tucks his big gun in to his jacket pocket. When he is running through the scanner, that big gun is now in his pants. (00:28:15)
Continuity mistake: When Tracy is tied up in the basement, the rope around his body changes styles between shots.
Visible crew/equipment: Near the beginning of the film when the police car explodes and flips over, you can blatantly see stunt wires used to aid in flipping the car. (00:02:45)
Visible crew/equipment: When a carload of bad guys drives past the front of Seagal's sister's house and riddles the front of the house with machine-gun fire, Seagal quickly slams the front door shut, and you can very clearly see all the stunt charges attached to the door.
Visible crew/equipment: When the Red October sub has surfaced to let the crew get off because of the supposed nuclear leak, there is a brief shot where you can clearly see the camera and its filming crew in their tennis shoes on the deck. (01:45:52)
Continuity mistake: During the fight in the pool, Lyon's big tattoo on his chest disappears. You can see a very faint blue shadow on his chest from the previous make-up.
Continuity mistake: When Bob gives Nikita her birthday cake, the positioning of the candles in the cake change between shots. (00:31:55)
Continuity mistake: Look at the station of the teller in the Racine bank. In the closest angles the pen by the calculator is at a perpendicular angle and touches the machine, while in the wider angles it is a bigger distance. (00:50:35)
Visible crew/equipment: When Darkman swings on the wire to save Julie, you can see a large wire coming out of his shirt to support his weight, and you can make out several large wires holding Julie in the shot of her being grabbed.
Deliberate mistake: When Steven Seagal and Kelly LeBrock are in the jeep, being chased through some fields by the cops, some of the shots of the jeep are flipped. Note the bullet holes on the windshield switch sides, as does the driver/steering wheel, the windshield wipers and the front license plate. As an aside, also note the numbers/letters on the license plate that have been altered via CG in the flipped shots.