FF to the place where Josie has already joined the school (still unpopular though) and is supposed to be sprinting back and forth outside when she meets up with her gym teacher to complain. When the shot is on the teacher, her hands on the teacher's shoulders. When the scene is of Josie talking, her hands are suddenly hanging down by her sides. That happens four or five times in that scene so you don't need a slow mo. It is pretty obvious.