Your description is not accurate. The teacher was giving a civics lesson and talking about the trial for the Charlie Hebdo massacre. He showed one of the sketches that the murderers were upset about. He warned Muslim students that he was going to show this and gave them a chance to leave the room. This apparently wasn’t enough to prevent homicidal rage in some people. The murderer was an 18 year old from Chechnya living in France whose family had been given refugee status by the French. Several members of his immediate family are being investigated for their involvement. I’m sure the French are wondering why the hell they give refugee status to people who are absolutely opposed to the French value of freedom of expression. Nobody in France is preventing Muslims from following Islam, but France is NOT going to give Muslims special status to prevent people from being offended. We don’t have the right to never be offended. I have run out of ways to explain this to fellow Muslims. I remember some years ago when, in the name of art, a museum in the U.S. displayed a crucifix (a cross with the body of Jesus on it) in a jar of urine. People were upset; they protested, carried signs, they had public prayers. But there was no violence. I don’t understand why some Muslims insist on acting like barbarians.