I had to read this fragment several times:
....was providing examples of unacceptable and dangerous opinions, citing “All Jews should be sterilized” as a belief that is deplorable.
It seems like the professor was citing examples of unacceptable opinions, including the one the girl has beef with as deplorable. She clearly wasn't paying attention, yes those words came out of his mouth, but that phrase was the only thing she heard. She didn't hear the part about him talking about perhaps other phrases, and him ending with these beliefs are deplorable. She completely missed the context and cried wolf.
So yes, when talking about some nasty topics, you might come across some nasty things to say, its all about context, and Grunfield seems to be asking for a watered down education of said topic. History is full of unfavorable things. But what good is it to cut out all the unfavorable, in favor of PC