Revealing mistake: When the UFO makes the huge flash that knocks everyone in the cemetery down, one of the police officers kicks a tombstone as he falls and it wobbles back and forth. (00:13:35)
Revealing mistake: In the shooting scene in the Mount Rushmore cafe, a boy in the background puts his fingers in his ears, because he knows the gun is about to be shot.
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: 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.