Factual error: At the "Battle of the Bands" scene, the kids arrive and have less than the length of one song to get ready to go on stage. (We see the band up on stage and hear the Battle of the Bands person tell the kids they're going on after that band.) Yet, when they get up on stage, they've got outfits, hair, makeup - including fancy braids and spikes - that just plain couldn't have been thrown together in five minutes.
Suggested correction: They're told they're on next, but it isn't known how long the gap is from one band finishing and the next one starting. The previous band can be heard playing as the parents are buying tickets. Then there's a cut showing the parents in the audience whilst no music is playing. We don't see the previous band leave, or the School of Rock go on. So it's possible there was a gap between the bands long enough for the costume change.
Plot hole: Mullins and the parents of the kids could not know that Dewey and the boys went to the rock contest and the location of that place.
Suggested correction: Maybe the bus driver told her. She could easily have phoned him when it was realised that the school bus was missing, as well as the kids. He could have told them exactly where the kids were.
