Continuity mistake: Ben-Hur places his crown on a table when he visits the fallen Messala, but upon returning the table and crown are gone. (00:36:35)
Continuity mistake: After the boy's Noel-Coward-lookalike father says, 'Et les fruits?', goes into the kitchen, and disappears out of shot, watch the cat on top of the bookcase to the left of the door. Before the boy runs into shot, the cat suddenly changes position and a mysterious lens flare appears on the right of the screen, showing that it's actually two shots edited together.
Continuity mistake: When Rick Nelson tells Angie Dickinson to throw the plant pot through the window to distract the gunmen who threaten John Wayne he seems to have had a hair cut between scenes as his sideburns are halved by the time he reaches the street and grow again later.
Continuity mistake: The escape train stops at a station at which another train has been the site of a massacre. One of the victims of this massacre has his head leaning out of a railway carriage window. As Kenneth More and Lauren Bacall from the escape train walk about the station, he can be seen raising and then lowering his head again as he realises that the 'take' is not complete.
Continuity mistake: It is supposed to be night when Joe slips out of the hotel, but a daytime sky is visible.
Continuity mistake: Frederick picks up a bottle of champagne out of the ice bucket and shakes it a little. As he does this the foil and wire are still on top. He turns and aims the bottle at his wife, then tips it back and the foil has vanished as he now just removes the wire and cork.
Continuity mistake: In the part when the two American officers are looking around in Anchorage, USA, and come across the dead woman at the News Studios you can clearly see her blink 2 or 3 times as the camera pans out.
Continuity mistake: The background shots of the Matterhorn show it with a clear sky, then a cloud around it, then a clear sky again. This keeps happening.
Continuity mistake: When Molly (Sandra Dee) grabs the letters she had hidden in the suitcase under the bed, her dress is still unzipped in the back. After ranting at her mother for having read the letters, she throws them into the fireplace, only now her dress is completely zipped up.
Continuity mistake: In the scene where we see Steve McQueen in a jeep waiting for the plane to taxi, he is chewing gum. He then he takes the gum out and sticks it on the top part of the windscreen frame of the jeep. In the next shot the jeep arrives where the plane is and there is no sign of the gum on the windscreen frame.
Continuity mistake: In the first close-up of the big evil that is Billy's brother, Lee Van Cleef's face is lit under a totally different light (when he says "It ain't the money that Brigade wants. Not the money at all"). (00:50:05)
Continuity mistake: When Richard Hannay jumps from the Sheriff's window into a passing truck it is full of bales of hay. The next time we see him in the truck it is full of sheep and the bales of hay have vanished.
Continuity mistake: Susie, a six-year-old girl, leans over a bathtub and reaches for a rubber duck. She falls into the tub but it obvious the tub has no water. (The actress, Terry Burnham, landed on a pad or cushion.) Immediately after she falls, there is a very noticeable jump in the film. Then water splashes up but the splash is much too high to have been made by the little girl. The next scene shows the mother entering the bathroom and the little girl, now completely drenched, standing up in the bathtub.