Continuity mistake: This film's set in the 50s, but the actors use 20 Austrian Schilling bank notes, which were only issued in the mid 1970s.
Continuity mistake: In the scene where Thunderbolt and Lightfoot are in the car with the crazy driver. The car goes over the embankment and as it flips you can see a wheel break off. A short time later they both drive off in the same car, with the wheel attached again.
Continuity mistake: After Burt Reynolds hits the guard in the crotch with the football, a wide shot shows 2:29 left in the game. He hits him again on the next play, and the scoreboard shows 2:35 left. The clock in a football game, of course, counts down, not up.
Continuity mistake: After Mr. Palmer walks over and tries to pick up Claude Mulvihill's gun (which Jack kicks away) we see Jack's hat on his left. In the next shot as Jake picks it up it's now on his right. (01:19:40)
Continuity mistake: When Hadrian jumps the mustang over the upturned car, the film slows down to show the jump in slow motion. When the car lands, it hits so hard the car spins around and ends up facing the cars it jumped. The scene is then repeated at normal speed, but just as the car would be shown spinning out, a shot of the car driving away from the accident is shown.
Continuity mistake: When Poirot and Mr. Ratchett first meet in the restaurant car, Poirot has to correct Ratchett's pronunciation of his name. Poirot then points with his right hand toward Ratchett, but when it cuts to a close-up of Poirot, both his hands are on the table. The angle changes back, and Poirot's hand is once again lifted.
Continuity mistake: There are a number of scenes (stable house, car, hotel) showing Claudia wearing a green harness dress. It is quite obvious that she is not wearing a brassiere in all of those scenes. In the hotel room, where Foxy and Claudia meet the judges, Claudia removes the green dress and is now wearing a bra. It would be highly unlikely that she would be putting one on, at the same time she is getting undressed. This was obviously done to cut down on nudity in the film. (00:41:30 - 00:47:45)
Continuity mistake: Bronson shoots the first thug in the lower stomach but the cops state that he was shot in the chest.
Continuity mistake: Right after the train is hijacked by Robert Shaw at 28th Street station, there are 2 additional hostages in the front car (for a total of 19) that disappear after the train is hijacked between 23rd Street and 28th Street.
Continuity mistake: Gene Hackman returns a second cookie to Harrison Ford's dish that he hadn't taken - or perhaps it's the same cookie he picked up and returned a moment earlier. Either way, the cookie had suddenly appeared in Hackman's hands going from one shot to another. (00:30:35)
Continuity mistake: When Buster and Billie are at Slim Mim's Jamboree near the end of the film, Buster is wearing an open-collar shirt. When they step outside to get some air, it changes to a button-down shirt and tie.