When The Bounty Hunter Falls From His Horse And Rolls To His Death His Right Arm Comes To Rest On The Front Of His Head. But When Caine Arrives In The Next Scene The Bounty Hunter's Right Arm Is No Longer Resting On The Front Of His Head But Is Now Behind His Back.
The style of music that the sax player Trim is playing is a form of jazz that was not around at that time. It is more in the style of Bebop, which was not heard until around the 1930s or 40s.
After pointing out the two big rocks the camera goes back to them. But they seem to have someone else in the woods. Just look in the back ground.