Revealing mistake: Despite being supposedly close to the North Pole, we never see the actors breath and their shadows should be long, but they are very short.
Revealing mistake: As Patrick McGoohan walks up the steps with a homing device, a crowbar swings out and strikes him in the head. Ernest Borgnine stops the swing just before striking McGoohan's head and McGoohan's acting takes over with him jerking his head back as seen in slow motion while falling down the stairs.