Factual error: The garage scientists are setting up an experiment. One of the guys goes to tighten the terminals of a battery. He grabs one in each hand and proceeds to tighten them. If he had done that to a real battery he would have gotten the shock of his life. (00:12:00)
Other mistake: The pie crust Mrs. Glover is rolling out is almost ready to be put into the pie pan when Bobby comes into the kitchen. Although not shown on camera, the motions of Mrs. Glover's shoulders and upper arms indicate that she continues rolling the pie crusts for some time, exerting a lot of pressure. Then she tells Bobby that pie crusts "should be handled as little as possible." (00:25:16 - 00:27:03)
Factual error: A scene in the second half of the film pans up over the top of the Flamingo hotel/casino facing north up the Vegas strip. The Caesars Palace sign is to the left (west) and north of the Flamingo are the Sands, the Dunes, and the Frontier casinos in that order. The Dunes hotel/casino was never located between the Sands and the Frontier. It was in fact one of the southernmost located casinos on the strip at that time and would have technically been behind, southwest of, the Flamingo in this scene.
Continuity mistake: During the showdown's sword fight between Lansing and Faisal in the palace hall, there is a far-off shot in which the blade of Lansing's sword can just barely be seen bending off at an unnatural angle, revealing it as a prop. For the rest of the duel, the sword is shown intact. (01:16:44)