Revealing mistake: At one point when the soldiers are walking through the jungle, one of them steps into a trap and is pulled up into the trees to be killed by Indians. However, if you watch this scene carefully, when the soldier (who steps into the trap) walks into frame you can see a wire already attached to his foot leading up into the trees. He doesn't step into a trap. (00:22:26)
Other mistake: The movie opens with a quote from Lewis Carroll, mistakenly credited as Carrol with just one L.
Revealing mistake: At the beginning, when the woman in the flotation seat is paddling backwards, you can see a fishing line attached to the back of seat that is being pulled to help her move backwards.