Other mistake: When the evil witches get their just desserts, Lois Leffour's friend Julia Whitman is choking on the Formula 86 bottle. Even though the bottle is small, Julia should have either seen it on the spoon, or felt it when she put it in her mouth. Instead, Julia swallows the bottle and coughs it up during her transformation into a mouse.
Other mistake: Before the Grand High Witch starts the meeting, Luke is watching the witches sit down, and he doesn't recognize the Woman in Black. This doesn't make sense because the Woman in Black attempted to kill him during the treehouse scene before any of them arrived at the hotel. The Woman in Black is even the first witch who tries to capture him when he runs on the stage.