Remember the seen when Ahnuld is running from the Predator and he falls off in the water then over the waterfall? Check out the scene as Arnold lays his face down in the mud. Then he sees the Predator jump into the water. Arnold starts to back up. You see mud all over his face. Except for the upper right portion of his face. The camera pans back to the Predator then back to Arnold. Wala. His whole face is now magically covered in mud. And he was crawling backwards. So he couldn't have layed his face back down in the mud again.