This was the response I got from my professor to a problem I had with a question on my last test. The question was worded very poorly for the answer that was supposed to be the correct answer and I had a problem with it so I told her so. It started with a nice email about how I thought the answer was wrong, it ended with me looking in the book of all books pertaining to Psychological Disorders (the DSM-IV) and proving her throughly wrong. (YES!!!)
In the end, the question was only worth .5 points, but it was more a point of proving her wrong... which I did and I got 80% of the credit!!!