Revealing mistake: In the scene out West with the buffalo, notice the car driving in the distant background.
Revealing mistake: When the parted Red Sea comes together, if you look behind Pharaoh as his troops are being engulfed by the water, notice in the background that there are two boulders floating in the water, not being pushed, but floating lightly.
Revealing mistake: In the scene right after they leave Scar's wigwam, when Ethan and Martin are speaking to each other around their camp you are able to see a small brown dot right above the sandy hills. This dot is the character Debbie's head while she is waiting for her cue before she runs in to the scene.
Revealing mistake: During the interrogation after the Albert Hall assassination attempt, the telephone used is an obvious Western Electric American-made phone instead of a British-manufactured telephone, betraying the fact that the interiors for the movie were shot in Hollywood.
Revealing mistake: When the German cruiser Graf Spee is seen leaving Montevideo harbour for the last time it is flying the American Stars and Stripes flag from the aft observation platform tower.