Continuity mistake: When Whinnie is dancing in front of Brad, and everyone is following her, the camera is doing a birdseye view and you can see a cheerleader stop dancing, but when the camera angle changes you see her dancing again, and then stop.
Revealing mistake: At the end of the movie when the cheer squad is shooting the video with Rhianna, she is wearing a blue shirt. The shots cut back and forth between the reality of them shooting the video in front of a blue screen and what the video looks like with the effects. If Rhianna is wearing a blue shirt and is filming this on a blue screen, she would appear to have no body when no one is behind her.
Continuity mistake: When Brit's friends ambush her at the football game they look through the fence and see Crenshaw heights cheerleaders wearing all white uniforms with no sleeves. When Brit and the others come through the gate they're all wearing long sleeved blue and yellow uniforms.