The professor was simply trying to prove that censorship, at any level, is a slippery slope. But, they couldn't handle the fact that someone would disagree with them.
On November 5, 2015, students at Yale University gathered on campus to protest an email sent by Associate Master of Silliman College Erika Christakis on October 30. Christakis’ email responded to a separate email from the school’s Intercultural Affairs Council that asked students to be thoughtful about the cultural implications of their Halloween costumes.
Christakis argued that the council’s email was infantilizing and threatened free expression on campus. There was also a concern that because the email was long, detailed, had 13 signatories, and links to acceptable and unacceptable costumes, it would not be interpreted as a rule. But rather it had the “color of law” implicit within it. The man that the protesting students are arguing with is Christakis' husband Nicholas. He is trying to talk sense to the students and argue in favor of free speech.