Character mistake: When the Grand High Witch and her assistant enter her room while Luke gets the formula, they're wearing pointy shoes. Earlier, it was mentioned that witches never wear pointy shoes.
The Witches (1990)
1 character mistake - chronological order
Directed by: Nicolas Roeg
Starring: Rowan Atkinson, Anjelica Huston, Jasen Fisher, Mai Zetterling
Revealing mistake: In the hotel meeting scene, the Grand High Witch tells the witches they can take their wigs off. When we see the newly bald witches, it is particularly obvious that only the foreground witches are ladies with bald caps - the rest of the witches are bald men. (00:30:10 - 00:31:00)
Grand High Witch: This stinking little carbuncle has had five hundred doses! Aha, we are having Instantaneous action.
Trivia: Roald Dahl hated the ending of the movie so much that he would drive past movie theaters with a megaphone and tell people not to watch it.
Answer: We've already witnessed Bruno being turned into a mouse so there's no need for us to see Lukes transformation as we already know how his transformation is going to be.