Other mistake: In Sarah's room, after the close-ups of Lancelot's empty shelf space and of Sarah beginning to say, "Someone..." as she finishes, "..has been in my room again," in this wide shot, while still on her bed until she leaves her room, there is a mark across Sarah's forehead that extends to the left side her eye. It isn't in the previous or following shots. (00:06:40)Super Grover
Other mistake: As the cannon the Goblin army brings rolls to a stop, the smoke jet used to simulate shots is visible.
Other mistake: When Sarah is at the end doing her speech with David Bowie in that upside down world and is meant to recite the speech word for word, she forgets the line "To take back the child that you have stolen" Instead she skips right over the line and says, " I have fought my way here to the castle beyond the goblin city - - missed line - - for my will is as strong as yours...etc. Etc."