The Mack Murphy Show tapes after sunset, as mentioned by Tori, which means Tori, Jade, Andre and Cat would've gone there at night. Although, during the scene change, it shows the front of Paramount Studios being daytime. Plus, when Beck was fixing Robbie's car, it was the middle of the day.
While waiting for André to show up at the Mack Murphy Show, Jade's hair is tied in a half ponytail. In the next shot, it is down over her ears, without enough time for her to take it down.
When André shows Dale the already cut together scenes, there is a thumbnail of Jade about to hit Cat which is also seen in the finished film at the end. If they have already shot it, and the end, with Jade wiping the knife, then they didn't need to shoot that part.
When Jade and Cat are shooting the last scene for the last time, Cat puts all of her hair on the left side of her head, and then lies down. But after she lies down, her hair is strewn about again.
When Dale gives them credit on the Mack Murphy Show, he doesn't give credit to Cat, but Cat was one of the main roles.