When the girls are about to throw Sasha into the lake, Cloe is wearing a long sleeved shirt, skirt and her hair in braids (Her school clothes). But a second later she is wearing a tank top with pants and her hair is down.
When the girls are practicing in the music studio, the guitar Cloe is playing is plugged into the headphones jack.
When Anna is practicing in the dance studio, as she listens to the girls playing through the wall, nothing is visible in the dance studio.
After Miss Higgins finishes giving her speech at the stage, behind the girls, Madame Demedov can be seen sitting still with a pink robe and sunglasses on.