Revealing mistake: During several of the driving sequences, the teenager in the driver's seat turns the steering wheel - but the rear screen projection keeps the car "moving" in a straight line. And it's particularly ironic in light of the movie's "big message" that the students here bear no resemblance to real-life teenagers in any real school. They're all slim, trim, athletic and model-gorgeous, as well as all-too-obviously not teenagers at all. (Because US child labor laws severely restrict the hours that underage actors can work, many films "cheat" by having youthful 20-somethings play the teens.)
Revealing mistake: In the taxi scene at the end of the movie, the steering wheel turns back and forth but the driver's hands are not moving.
Revealing mistake: Have a look at some of the beards (and wigs) in this movie, the facial hair is coming loose on several of the disciples' beards.
Revealing mistake: During the initial dive the hydroplane on the sail (conning tower) is pointing upwards. During a later dive the hydroplane is pointing downwards. Wouldn't one position cause the submarine to surface?
Revealing mistake: At the opening of the film as the pirate ship passes left to right the flags are blowing in the opposite direction of the ship's movement and the sails keep blowing back although the ship keeps moving forward. Notice the large amount of churning water at the ship's rudder indicating that the boat is powered by a motor.
Revealing mistake: If you watch closely when the prisoner hits Jake with the shovel you can see the shovel bend as if it was rubber.
Revealing mistake: At the wine tasting, Lily pushes the waiter. It is obvious that the glasses on his tray are stuck to it, as they don't move even when he turns the tray on it's side.
Revealing mistake: On the maiden flight of the X-15, the B-52 that carries it to launch position has several silhouettes of the X-15 painted on it, obviously one for every time it carried the X-15 for a mission. Clearly the real B-52 they used for X-15 launches and they didn't account for the fact that this was meant to be the first. (00:48:50 - 00:50:05)
Revealing mistake: The sea creature Gorgo is paraded through the streets of London on a flatbed tractor trailer, and an off-screen American newsman announces the monster's arrival at Battersea Park, where it will be exhibited at Dorkin's Circus. The announcer introduces the creature's owners as they step from their motorcade, saying, "And our own Mr. Dorkin, of Dorkin's Circus, in the checkered suit." Problem is, Mr. Dorkin is wearing a plain gray flannel suit. Closeup shots of Mr. Dorkin over the next 40 seconds reveal that the suit is not checkered, not plaid, not striped, not patterned in any way at all. It's simply a plain gray suit. Apparently, the announcer's pre-recorded lines were never modified after changes were made in costuming. (00:34:05 - 00:35:00)