Visible crew/equipment: From the video version: When Books (John Wayne) is shot in the back by the bartender, you can clearly see a rope fastened onto the heel of his boot that is being pulled to help him stumble and fall onto the floor as the second shotgun blast hits him.
Continuity: A couple of times in the movie, the camera pans to John Wayne, and his hair is parted on the wrong side. (Reverse editing flaw).