When Samantha and Heather are in the woods, Samantha attempts to tell Heather about the school. During the first screen shot directed at Heather, Samantha can be heard speaking but her jaw is not moving.
The teacher's lecture on an 1809 war between Austria and France is pure nonsense. Although Austria was at war with Napoleonic France during this time, the conditions described do not match reality. In addition, the teacher mentions the Germans despite the fact that the German state was not established until 1871.
When Heather sits down to eat with the girls for the first time, she is holding a plate of mashed up cake, she is told to pull her socks up by one a girl, the camera flashes to her socks then back to her and the cake is now whole.
Samantha trows a glass of milk at Marcy's face. After that, Heather punches Samantha and the girls quickly get in a brutal fist fight. In the next shot that shows Marcy, her face and chest are completely dry and clean, with no traces of milk whatsoever.
(at around 1h 05 mins) During the car accident scene, when Heather's mother is killed and her body is placed on the car's side, the global view from above given by the camera going progressively up reveals a numerical error or an omission: At the beginning of the global view, wood and branches can be seen going from the mother's legs, running against the car's wheel and going toward the road. Some branches put on the ground also are visible under the car. A few seconds later, while the camera goes up, the branches suddenly disappear.
Towards the end, when Dr. Fasulo is in the hospital, he talks to Ms. Traverse who is on his right side. In the next scene, Ms. Traverse walks over to his left side, but in close-up shots, he continues to look to his right side while talking to her.