When Duval rapes Agnes, he puts his left hand over her mouth. In some shots, his right hand is over her mouth.
The length of the ash on Sarah's cigarette varies greatly when she is telling the red book story to Agnes.
During the basketball game, Agnes' coach was allowed to call a timeout when her team was not in possession of the basketball.
The 45 record would not play properly without the adapter in the center hole. The record would slide around the turntable once the needle was placed on it and the music would become distorted and the speed of the music would vary - it would continue to speed up and slow down during the entire record.
The basketball game is a "five on five" game. High school girls played "six on six" basketball in Iowa until 1984.
When Agnes walks into the building to play her basketball game, the camera and operator are visible in the glass doors through which she enters.