Visible crew/equipment: When Norman is hit by the bundle of newspapers he is thrown in the air and you can see the wires lifting him.
Continuity mistake: During the search for Debbie; Margaret's scarf on her head disappears and reappears several times.
Continuity mistake: The cars change shape frequently during the movie. That depends on the fact that many scenes were filmed at real races, with real F-1 cars. The cars that the actors drove were, for the most part, disguised F-3 racers. There are at least three fake Ferraris, and they all look different. One of them seems to have been built to resemble a 1965 F-1, but altered to look like a 1966 model. The non-existent Yamura (built to resemble a Maclaren), that James Garner drives is actually two cars with different chassis, one of them seems to be used very little, except when it catches fire in a scene.
Continuity mistake: Helen attacks Diana in Dracula's castle and is burned by Diana's crucifix. In a jumble of shots Helen reacts to the burn; Diana is seen holding up the cross, then not holding up the cross, and then holding it up again. (00:59:20)
Continuity mistake: Throughout the movie Elsa wears a collar. In the scene where she runs away the collar is visibly in place - a few minutes later, when she's found with the elephant, the collar has disappeared.
Revealing mistake: All four of the Dachshunds in this story are supposed to be female. During one part of the picture, when they jump on the bed with Suzanne, you can see that at least one is male.
Revealing mistake: Near the beginning, Montag puts on the fireproof clothing to use the flamethrower. It's really footage of him later taking off the same equipment played in reverse.
Continuity mistake: When the dinosaur charges toward Tumok, and Tumok lies down to shove the spear into the creature as it runs upon him, the dinosaur looks several times bigger than it did in all the previous scenes.
Audio problem: When Alfie and the other mechanic are at the shed, the mechanic asks, "Are you getting serious with her?" and his mouth is not in sync.
Factual error: Racer Dave Owens goes down to an unspecified Southern state to race and becomes a moonshine runner. However, the Dodge he drives in his illicit activities possesses California plates, as does the Plymouth driven by the IRS agents.
Factual error: Cary Grant arrives at his Tokyo hotel two days early, and no rooms are available. He goes to his embassy, which, according to the sign on the gate is the "British Embassy". In reality, the sign would say, "Embassy of the United Kingdom of Great Britain and Northern Ireland".
Revealing mistake: In the last scene, when Chris is leaving, it shows several shots of the peaceful village. Each time they show the village, in the middle of the square is what looks like two boys fighting. One punches the other and he falls down and gets up and punches back and he falls down. They do that about three times.
Continuity mistake: In the scene where Paul Newman seduces Shelly Winters in the nightclub, they're dancing to the sounds of a brass band, even though the musicians are all holding guitars.
Continuity mistake: As George says "That you people are rearranging my genes so that everyone will be like everyone else" he puts his left arm around Nick. His hand, though is on the back of the sofa. Instantly in the next shot, however his left hand is now on Nick's left shoulder.
Continuity mistake: On the airplane, Rock Hudson takes a pillow from the stewardess, and puts it behind his head. They cut away to the stewardess, and back to Hudson, and the pillow is gone. They cut to the stewardess again, then back to Hudson, and the pillow reappears.
Continuity mistake: When Wyler and Susan are escaping in the van, the windscreen is shattered and Wyler punches a hole for visibility. In all further shots of the van, the windscreen is obviously intact with the shattering merely cosmetic.
Revealing mistake: In this scene we see Frank Sinatra in a diving suit and helmet being lowered into the sea to look for a sunken submarine. As he is being lowered you can see the sun's reflection on the walls of a tank, meaning it was filmed in a large tank of water.
Visible crew/equipment: During the flashback scene in the clock courtyard, there are multiple T-marks (plastic type) visible on the ground, near Col. Marcus and Gen. Randolph. (00:16:20)
Factual error: The uniforms worn by the engineering force are from the wrong era. Prior to 1941 the left arm rates had the head of the eagle pointing to the wearer's rear. Steve McQueen and the rest of the Engineering force rate eagle head is pointing forward, which is from WW2.
Plot hole: All the teen girls are about the same age and always in the same grade-level during their three years at St. Francis. There are no younger new students arriving each fall, nor do older ones graduate in the spring. Every student graduates at the end of the three years. Schools do not accept a new crop of students every three years.