At the 36 min mark, Caroline's hair is mussed from a previous take of putting her bonnet off and on.
At the first confrontation with Mr. Slater the fence behind him is 1970s mass produced.
The Ingalls children try to fool Bartholomew by having him think a papier-mache boulder was real and that Albert was a werewolf that could hurt him. Even if Carrie hadn't ruined their plan, Bartholomew would have known the truth when Albert brought the boulder to class and there would be nothing to stop him from going back to his bullying ways.