Plot Question about the Movie "Deliverance"?

In the movie, Jon Voight's character scales a cliff to stalk the toothless Mountain Man he'd encountered earlier. When he manages to kill a man with an arrow, he quickly examines his victim's mouth, and finds that the man HAS TEETH. He whimpers "no!" a few times, as if he realized that he's killed the wrong man. It can't be the same man from the scene, unless he had dentures. Did Drew really get shot, or did Lewis say that for "drama"? Some viewers say that you can hear a gunshot over the noise of the rapids, if you listen carefully. (I can't).