This slip up occurs in the scene where the preacher is shot. As the preacher falls, his back is to Gabriel & he's holding the musket "right handed," meaning the stock is on his right (screen left) & left hand on the barrell. He then tosses the musket over his head and backwards to Gabriel. But as Gabriel catches it, notice that the stck is now on Gabriel's left (screen right) with the barrell pointed to screen left. It somehow, for absolutely no reason, flipped completely around.