If they chose to withhold his diploma for the atrocious misuse of spelling and grammar, that might have been understandable.
But holding him out of graduation because he asked classmates to go and discuss something at a public meeting? That’s insane.
Of course, as with many of these stories, we are only seeing a partial view of a single side of things. There may be more going on that the alleged victim wants to discuss.
It's quite an experience to undergo a Judicial Board hearing and watching an internationally-known philosophy professor act like a NAZI judge.