Revealing mistake: During the chariot race, where the contestants are riding towards the screen, tyre tracks from the camera vehicle are clearly visible imprinted in the sand. (00:20:50)
Revealing mistake: The bullet hole gouge in the window frame near Ricky Nelson and the outward facing splinters at the bullet hole in the door frame near John Wayne indicate exit holes.
Revealing mistake: In the scene where the girl is going to shoot Vincent Price watch closely as she pulls the trigger. You can see the wires pulling the gun from beneath to give it the realism of the blast.
Revealing mistake: When Spats Columbo's gangsters are being searched for weapons at the Florida Hotel, the man doing the pat search can be seen placing the gun behind the gangster's leg, just before it supposedly drops out of his trouser leg.
Revealing mistake: Watch the back projection of the Great Northern desert in the train carriage windows. At one point a lorry appears, waiting at a level crossing for the train (that the film was shot from) to pass.
Revealing mistake: A driver pulls out into oncoming traffic and hits another car, It is obvious that when the scene was filmed, the driver stopped just short of the other vehicle. The sound effect of a collision is dubbed in and the front of the two vehicles is never shown.