The Oberlin dean didn’t just say the bakery was “racist,” she said they had a “long history of racial profiling.” That’s a critical distinction. The first amendment doesn’t directly protect falsehoods. But to give wide berth for free expression, we have carved out all these situations where even a false assertion will be protected: parody, hyperbole, opinions, assertions made based on good faith investigation, etc. If the Oberlin dean had, for example, said the bakery was racist, based on the fact that the bakery failed to consider that calling the police on a black student would subject the student to far graver consequences than under identical circumstances where the student was white, that would arguably be a non-falsifiable opinion, or a statement about someone’s “general character.”
But she went beyond expressing an arguable opinion. Saying that someone has “a long history racial profiling” is an assertion that a pattern of concrete events have taken place. It’s not an assertion about someone’s “general character.” It’s falsifiable. Moreover, the dean couldn’t even construct a fig leaf, some post hoc rationalization, to defend that assertion. She all but admitted she had tried to destroy someone’s business based on the equivalent of a “fake news” Facebook post.