After Lucas gets in a fight with the carny people, he comes out of it with blood running down the corner of his mouth. After Mark leaves the scene Micah and Lucas start walking and Lucas reaches up to spot the blood. The camera angle changes and now there is not blood anywhere on his face.
When Jay Jefferson confronts Micah, Luca's and the real Pete Dawson, Pete Dawson is on his horse. After the gunfight, there is no rider on Pete Dawson's horse.
When Jay and Curley are playing poker, the camera shows each hand. It just so happens that both men have a ten of hearts in their card hand. This was with only one deck of cards.