In the first Hulkout, you can see some of the flesh beneath the green paint on Ferrigno's face. Also, throughout the entire Hulkout, every time Lou lifts his foot, you can see that the bottoms of his feet were either not painted, or that the paint is wearing off. This is especially obvious near the end of the Hulkout.
Running down a road, Kathryn Leigh Scott completely wipes out. She stays put for a couple of seconds (most likely awaiting the Director's instructions - which apparently were to continue), then gets back up, continuing the run.
The name of Bruce Wright's character is Joey Malone, but the character's name is erroneously listed in the end credits as "Richard Sloan."
When the Hulk flips the jeep into the river he can't be seen behind it. He should be standing right behind it if he had just flipped it.
At 10:27 David "Bailey" says "You certainly did" but his mouth doesn't move.