Continuity mistake: When Morgan is shot while playing pool he is placed on the pool table. An overhead shot shows a wide pool of blood spreading from his right side. In a subsequent shot the pool of blood is much narrower and a completely different shape.
Continuity mistake: When Wyatt meets Doc for the first time, the amount of liquid left in Doc's drink keeps changing.
Continuity mistake: When Doc confronts Ike looking to fight there are a lot of people around. Then from the camera angle from behind Wyatt there is no-one around.
Continuity mistake: When Wyatt is confronted by Ed Ross in the bar after refereeing the boxing match toward the beginning of the movie, he has a pistol in his belt when throws the cue ball at Ross. Wyatt still has the pistol in his belt when he takes Ross' gun and holster and straps them on. But when he and Sally walk outside right after, the pistol that was in his belt is gone.