Revealing mistake: After King Kong destroys the train track of the oncoming train, in the POV shot directly behind the train operator while he watches Kong rise from the broken track, the small model's support control bar is visible at the right as it moves up and down. The next shot is a close-up of the shocked motorman, and after he attempts to stop the train, there's another shot facing Kong with the control bar visible for a moment. (01:31:50)
Revealing mistake: When Denham is rowing the boat to the island - an obvious rear projection - the oars never touch the water.
Continuity mistake: In this 1933 Mickey Mouse short, Mickey dreams he is in a mad doctor's castle. He opens an inner door and finds a second door behind it. He then finds a third, fourth and fifth door. When a sixth door swings open and he is able to enter the mad doctor's lair, the other five doors have vanished.