In many scenes of this episode, there are posters of Stevie. The outfit that Stevie wears in the posters is the same outfit Stevie wears during the middle scenes of this episode.
They could have at least made an attempt to give some kind of backup band to Stevie. There was clearly band music playing to her singing, yet there wasn't a musical instrument in sight.
After Zack is pronounced the winner and has to go to Belding's Office, how can Milo not have heard the announcement and stop Zack when clearly Zack was called to Belding's Office.