Thats like walking up to every student and whispering "Your mom was a stupid whore" and then chastising the kid who's mom died early in life when he explodes. The point was to show how symbolic gestures can affect some more than others and figure out why. And this idiot used his disdain of the kids belligerency in his punishment instead of accepting what he did. "It was in the book" isnt a good enough reason not fully subvert blame when purposely instigating.
He should have told the kid "Thank you for your position would you care to please explain more to the class to they can perhaps understand this lesson better?" and tried to calm him down instead of instantly punishing him for his "extreme" belief.