Unless he gave information about this student that would have allowed her public identification, it is not a violation of FERPA. Describing a person to a group that doesn’t have any knowledge of the students in his class is not going to allow them to identify a particular student. I don’t think that a FERPA violation would hold up in court. I’m assuming he didn’t actually name her, of course (if he did, he’s in trouble).
Talking smack about your employer can land you in hot water, though. Nothing in the article explains how this professor’s comments became public … I know that anyone can out anyone else, and you should always assume that someone will try to get you in trouble if you say anything about your employer. Someone on that listserv decided to get him in trouble, and if they provided the school administration with evidence that he disagreed with their decision, that would likely make them want to get rid of him. If their own rules prohibited them from firing him for that, I could see them making the stretch of FERPA violation. Again, based on the information provided, I don’t think that would stick in court. But his career as a professor is probably over, regardless. And honestly, it sounds like a terrible place to teach.