Continuity mistake: During the detention scene, the teacher comes in and you can see there isn't anything on his rear end. As he leaves, you can see toilet paper hanging from his rear. This was because a scene never made it into the movie where the teacher's office is in the mens restroom. Also confirmed on cast commentary.
Continuity mistake: When Janey is laying on the couch talking to her dad, in the closeup shots her hair is perfectly neat in the ponytail. From distance shots, some of the hair on top of her head is out of place. Then at the end, the father ruffles her hair and it matches the misplaced hair seen earlier in the scene.
Continuity mistake: During the football game against the North Compton Wildcats, Reggie Ray gets all woozy. If you look at the scoreboard in this shot it says there is 1:15 left in the 4th quarter. After the trainer talks to the coach the board says 1:20 left in the 3rd quarter.
Continuity mistake: Just prior to Janey and her dad having their Father-Daughter talk on the couch, we see from over her shoulder that her robe is closed. The next shot of her though (looking down) her robe above the waist is open. In both shots she is either sleeping or dozing so would not have opened it herself.
Continuity mistake: Towards the end of the football game when Jake throws the ball on the scoreboard there are 32 seconds left and where it says "Reggie Ray's Concussions TO GO" it says either 10 or 0 where as before it said 1. But when Reggie gets hit with the football the scoreboard goes from 1 to 0 and the timer as at 0:00. It is unlikely that that whole play took a full 32 seconds.