Visible crew/equipment: The furry suits the "mole men" are wearing clearly show the zippers up the back when one of them is going down a well.
Continuity mistake: At the end of the film when all the women are dressed up after making clothes out of tablecloths, you can see the Italian woman riding in the front of the wagon. The shot changes and she's riding on the side looking at all the men and smiling. The shot changes again and she's back to the front.
Revealing mistake: When the boat is supposedly surrounded by a swarm of flies, they're really just relatively few flies trapped between two panes of glass in front of the camera lens. Evidence: whenever the camera moves, the "swarm" moves with it against the background, and you can even see some of the insects walking on the surface of the glass.
Continuity mistake: At the detective agency, while Bud and Lou are talking to the murderer, the description of the murderer comes over the police radio, and it states "5 feet 11 inches, weighs 165, blue eyes, brown hair, last seen wearing a felt hat and dark borwn overcoat". Then 15 seconds later Bud says out loud, writing on a piece of paper the description "5 feet 10 inches, weight 165, blue eyes, sandy hair".
Revealing mistake: The Thing takes a swing at the captain after the captain opens the door. As the Thing swings his arm, he takes out a chunk of wood out of the door. If you step through the frames on the DVD, you can see the wood leaving the door a full second after the Thing has hit it. A small explosive charge that was not in sync with the actor. You can also see the outline of where the wood comes off before he swings his arm. And one more thing, his arm does not touch the door or even comes close to where the wood comes off - a safety precaution I presume. (00:57:33)
Factual error: John Wayne's squadron lands on Guadacanal as part of the "Cactus Air Force" in August 1942. However, they are flying F6F-3 Hellcats, which were not available, even to the Navy, until the middle of 1943. To top it off, they are painted in a late-war camouflage scheme with late-war markings.
Factual error: All of the Lydia's lieutenants are wearing epauletes on their left shoulders.only lieutenant commanders were permitted to wear one on the left shoulder, while the right shoulder was reserved for captains of less than 3 years' seniority.
Revealing mistake: When Captain Quincy Wyatt interrogates a captive Seminole Native American by threatening him with a poisonous snake, the native is safe because there is a protective piece of glass between him and the snake. The snake's reflection is quite obvious on the glass panel. (01:14:40)
Revealing mistake: When The Indians launch their final attack (towards the end of the film), on a old outpost held by a small group of soldiers, Ward Bond is hit by a arrow which enters the right side of his chest. In the next shot you see Gregory Peck removing the arrow from the left side of Ward Bond's chest.