Early in the show, Buddy is offended when Georgie tells him that he's reading the book upside-down. Buddy grabs Georgie and draws his arm back to hit him but when the punch is actually delivered in the next scene, Buddy and Georgie have switched places.
While Lucas is getting held and punch the camera shows Mark standing by the wagon with George and he his hair is a mess hanging straight down. But when Mark jumps on one of the cowboys and thrown to the side, Mark's hair has returned to the normal combed and bushed over to the right look.
There is an obvious stand-in actor for Dub (John Milford) after Lucas confronts him and Buddy attacking George in the barn.