At the end, where Chris is shaking hands with one of the other soldiers who was allowed to leave on the helicopter, the straps of bullets across his chest were crossed. Then, after the hand shake, they were each on one side.
During the scene in the village when they are in the hut and making the Vietnamese kid with one leg "dance" while shooting at him, and then "Bunny" kills the same kid with the butt of his shotgun, Sergearnt O'Neil is standing in the doorway and has a cigarette in his mouth that seems to get shorter and shorter, then longer again. It's very obvious once you notice it!