Revealing mistake: The man from Mars is in an elevator with a woman when the power goes out. He tells her he cut the electricity and gas powered engines all over the world for a half an hour. They proceed to show clips of the power out in different parts of the world. When they get to Big Ben in London, you can see a motorboat cruising down the river in the background. If the boat were powered by wood or coal, there would be plume of smoke trailing it. If it were powered by oil (ie. diesel) electricity is required to pump the fuel into the ejectors. (01:02:05)
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)
Suggested correction: It is not a full second delay. It is four frames which translates to 1/6 of a second. Everything described in this entry is only visible if you step through frame by frame which invalidates the mistake.
Revealing mistake: During the first shot of the rocket ship coasting through space stars can be seen through it.
Revealing mistake: When Lou and Tommy are in the car at the park, and Tommy is taking the disguise bandage off his head, a very faint outline of Tommy's head is visible under the incomplete special effect.