Revealing mistake: During the transport of the POWs by train (which starts about 26 mins into the film) the number on the side of the engine is visible as 719. About 3 mins (filmwise) into the journey it appears in mirror image. It appears they filmed the train moving from right to left, but throughout the film the train moves from left to right, so the film must have been reversed. It happens twice, the second time 14 min 24 sec after the first. (00:29:34)
Continuity mistake: In the opening credits, when Smart gets inside the phone booth, the doors are not fully closed, but the immediate close-up angle shows them fully closed.
Continuity mistake: Ann visits her mother's grave at the cemetery with her father, who wipes off snow from the mother's photo on the marble. Couple of minutes later, a new shot shows the photo covered in snow again.
Other mistake: Near the end of the movie there is a montage scene of acceptance letters being printed followed by the reactions of the various people who received the letters. Despite these form letters being sent on the same day the date on some of the letters is April 11, 1988 and the date on others say April 11, 1989.
Continuity mistake: When Banner changes into Hulk in the subway station, his beard is gone. When Banner changes back after his "Hulk-out" his beard is back. (00:16:00 - 00:18:00)
Continuity mistake: The box of Marlboro cigarettes next to Buster's [Kiefer Sutherland] left hand did not have a lighter on top of it, but there was a lighter atop the pack after an angle shift. Buster was holding a newspaper with his left hand and had a cigarette in his right, so the lighter just suddenly appeared. Seconds later, the lighter was gone. (00:04:34 - 00:05:02)
Visible crew/equipment: Early in the movie Nancy visits Penelope. As she steps out of her car, the overhead microphone is visible in the front windscreen. (00:15:30)
Plot hole: They seem to break a lot of rules in the main event between Mimi Lesseos and Jan Mackenzie's. They brawl outside the ring long enough to be counted out, choke outs on the ropes long enough to be disqualified are some examples.
Continuity mistake: When Alex is speaking with Christopher in their dorm room she's wearing a pink top with the right shoulder down. Then it's pulled up in one shot before being back off the shoulder again.
Continuity mistake: John Ritter's beard goes from being real to fake throughout the movie.
Continuity mistake: When Fuller falls to his death, the mannequin used as his stand-in gets decapitated on its way down. It even makes a loud noise. When Fuller lands, however, his head is still on his shoulders.
Visible crew/equipment: When Mookie throws the trash can through Sal's window, the reverse shot from inside the restaurant reveals the main camera, in the lower left portion of the screen, moving in towards the window as it's smashed.
Character mistake: Despite being blind, Erika Breen's able to locate light switches and door knobs throughout the movie without feeling for them like a blind person would do.
Character mistake: When Eric Roberts' character receives his letter at the start of the film it says "congradulations." instead of congratulations.
Revealing mistake: Obvious stuntman in a flame resistant suit when Eric's on fire.
Continuity mistake: When Harry throws back his arm to break the bodybuilder's front door with the crowbar, the front door and the object mounted on the wall are in the sun but as the camera changes angles where he actually finishes his swing and breaks the glass on the door, suddenly the door and object on wall are fully in the shade.
Continuity mistake: When Lucas visits Meg at the juvenile home, he carries a stuffed toy monkey by the leg. When the camera angle changes, he is holding the monkey by the neck. (01:08:15)
Continuity mistake: In the beach scene the boys are eating ice cream cones. The ice cream keeps changing size.
Revealing mistake: When the Russians are in the Finn's trench, you see the Finns stabbing the Russians. If you look carefully, on a few of the Russians you can see protection visible. (00:48:45)
Other mistake: At the beginning of the film, there's no way Angela would possibly have been able to know the exact moment the girl would have been walking down the street and what she'd be wearing so she could be wearing the exact outfit.