I'd like to point out that if the teacher was trying to make students think, what he would have done is started a conversation among them unbiasedly and played severe devils advocate to each student no matter what side of the issue he or she was on. Being lectured causes the brain to go into a mode that doesn't really allow it to think as critically as in discussion--and although I didn't read the transcript, it seems to me from what I saw on the board that everything the students did say was only said because they were led into it.
Also, I like the point in the article in which the attorney says that the student wont be sued because he, too, has a right to free-speech. Considering, according to the lawyer (who I cannot say I believe), that the student essentially misquoted the teacher by pulling quotes out of context and, essentially, framed the teacher, the first ammendment must cover a lot more than I had ever imagined, or that man must be a stupid, unaware and/or lying sack o' potaters.
I don't care if people sue over injuries for compensation when there is really obviously fault on another party. However, when people sue for being injured at, say, a casino and falling and hurting themselves, that should not be allowed. No, screw you you klutz, learn to walk.