I wonder if they would of taken "who is the Doctor?" - especially as the the character has been creditted in as The Doctor since the late 70s iirc
The judges are usually pretty good about accepting alternates, and had a player been marked wrong for the answer, there would have been an open-and-shut case for an appeal. But any question-writer savvy enough to know about Matt Smith and Doctor Who would have undoubtedly written down "Who is Doctor Who" or "Who is The Doctor" as correct responses.
Alex