Revealing mistake: When the Enterprise is leaving its docking station and pulling out, two little bugs or debris from the model lands on the camera lens on the lower left corner (corrected in the Director's Edition).
Revealing mistake: In the major helicopter scene when Ride of the Valkyries is played, the actual tape isn't going over the playing heads. (00:37:29)
Revealing mistake: As the gang is being chased through the "96th Street Station", you can see the true station name "Hoyt" (as in Hoyt-Schermerhorn Sts. Station) on the outer station wall. (00:42:50)
Revealing mistake: When the motorcycles are chasing the guy and his girl in the red car, one of the motorcycle riders attacks the car with a machete. He first hits the side of the car, and then goes to hit the windshield. Notice the windshield is already cracked prior to the machete making contact.
Revealing mistake: The British intelligence officer Wells, who is being trained to infiltrate the Gestapo headquarters at Lyon, would never pass as a German because of his slight but still quite noticable accent. (00:47:45)
Revealing mistake: During the laser battle inside the space station, one of the villains on one of the upper circular tiers makes a move as though to signify he was hit with a laser a second or two before the laser actually hits him.
Revealing mistake: When Dan Holland, Kate, V.I.N.CENT and old Bob battle Reinhard's robot sentries on the catwalk, part of the bridge the sentries stand on is critically damaged and collapses. In that shot, the sentries are model figurines.
Revealing mistake: When Sweetums scares the girls out of the tent, watch the first girl that runs out screaming. If you look at her face closely, you can see that she is smiling.
Revealing mistake: The bayonet used by Private Williams after the death of his Sergeant Major is flexible and made of rubber.
Revealing mistake: In "The Plot to Kill a City (Part 1), before Buck is "levitated", you can see the black wires meant to lift him.
Revealing mistake: When the purser's safe falls through the ceiling, the ceiling metal is far too thin. Bearing in mind also, that the on the other side of the ceiling metal is supposed to be the floor of the next deck up, and that too is a thin flimsy metal, that doesn't even appear that it could support any kind of weight.
Revealing mistake: Just before the battle between King Arthur's men and Sir Mordred's men, Trimble Tom escapes from Sir Mordred's encampment in a rocket-powered chair. As he approaches King Arthur's Castle you can see the wires supporting the chair. (01:15:45)
Revealing mistake: In the closeups the boy is holding a large leaf of seaweed to offer the stallion. But in the long shots at the waterfront he extends an empty hand with no seaweed visible.