Unless the teacher planned on getting fired with a lot of publicity, I think this was by mistake. At time passes from those horrible events people will get stupid about them and do things when they are oblivious to the real meaning. In debate class I once was asked to debate from the side of the Soviets on why they should have a large nuclear presence. Our teacher was not pro-soviet, just putting the other side out for the sake of class and learning. The teacher likely is uneducated on the history of the issues and simply picked one that is sort of well known, but not in detail by their self.
One dead, three injured in Northern Arizona University shooting (DPA)
from the article: U.S. teacher's assignment to students: Explain why Jews are evil