Continuity mistake: In the scene where Roger and Hoskins are moments away from crashing into a bridge in the cab quickly look at the road there is no gate in between the roads. But when they jump onto the bridge they crash right into a gate. (00:57:15)
Continuity mistake: When the "I LUV YOU" picture is viewed in Nordberg's hospital room, the photo has a vertical/portrait orientation. When Frank shows the picture to Jane, the photo has a horizontal/landscape orientation. (00:12:50 - 00:38:25)
Continuity mistake: In the basement of the Orpheum theater, Holmes takes a lamp off of a wall and places it on the floor. The shot cuts, and the lamp is back on the wall. When the shot cuts again, the lamp is back on the floor. (01:29:25 - 01:30:45)
Continuity mistake: Near the end when they're entering the Mexican village, Billy's coat disappears as he rides through the gate. (01:17:45)
Revealing mistake: In the barber shop scene at the end of the film, Agent Anderson terrorises Deputy Sheriff Pell (who has a full head of hair) with a razor blade. Anderson throws him across the room, but the person being thrown across the room has a mostly bald head.
Revealing mistake: When Jemma enters the headshrinker's laboratory, there is a table with three heads on it each encased in glass. When it goes in close-up on the middle head, you can see that the table has a hole where the actor can slip in his head.
Visible crew/equipment: When Jamie Lee Curtis is leaving John Cleese's office, she kisses him goodbye and calls him Uncle. After she has left, you can clearly see the cameraman move into view of the mirror. (00:33:27)
Continuity mistake: When Harrison Ford is on the rooftop and the suitcase accidentally opens, the Statue of Liberty goes flying off the rooftop and on to the ground, several stories down. In the next shot, the little statue is perched at the edge of the rooftop. Also, the clothes that fly away magically reappear next to the suitcase a shot later.
Continuity mistake: Inside Lord Peel's study, Poirot asks Lady Westholme what did she do after lunch, since "You did not immediately go for your walk, I believe." Peter Ustinov poses the question with his hands behind his back, but Lauren Bacall's answer answers with the stand-in for Ustinov posing with his hand on his hip. (00:54:40)