Vereena's tray as she purchases cigarettes from one of the cooks. The plate is on the tray, then on the table as she removes the cigarettes, then it is on the tray again.
During the scene with Mrs McVane where Verena is informed she is to be expelled, the cigarette she is holding changes hands between shots.
When Snake and Tinka are dancing and the camera is on Snake, the straps on Tinka's dress are in the right place on her shoulders. When the shot changes to Tinka, the straps are hanging off her shoulders. They keep changing between shots.
During the field hockey game, as Odette and Verena argue over their different stances on their school becoming co-ed, Verena's hair keeps changing between shots, alternating between down the front of her shoulders and down the back of her shoulders.
The color and style of Odette's riding pants change between the outdoor and indoor shots.
The cherry-picker truck used by the Flat Critters to get to Tinka's window was a Ford C-Series cab-over. While this truck was manufactured between 1957 and 1990, the cowl insignia combined with reflectors indicates this is a model made after 1968, five years after this movie takes place.