Continuity mistake: Near the end when they're entering the Mexican village, Billy's coat disappears as he rides through the gate. (01:17:45)
Continuity mistake: In the scene before the race, the butler is leaning against the wall smoking. When he gets off the wall, there is a large grey smudge on his black suit, but the next time we see the back of his suit there is no mark. (00:13:00)