Factual error: When the Hulk jumps up and grabs on to the tail of the helicopter, he is somehow able to hang on to the tail while spinning the helicopter in a circle. Helicopters require a certain weight distribution in order to maintain stabilized flight. Someone of the Hulk's size and strength wouldn't be able to just hang on to the tail and spin the helicopter. He instead would bring the helicopter crashing down.
Continuity mistake: When Bruce is rappelling down the shaft, at one point he turns his body face down, and you can tell by the rate at which the background is passing by that he is instantly going slower than the previous shot. If anything, his speed should have increased since he's no longer in a position to slow his descent by using his hands to rub against the rope.