Continuity mistake: In the flashback scene (where Cassie has the crazy long hair) we see "young" Cassie perform a routine in the studio. Zach comes out of the shower towelling his hair and watches her. We see his hair is messed up having just been roughly dried with a towel. The next shot is Cassie dancing, then the next shot is back to Zach, and this time his hair is combed nicely down.