As far as I understand Kurts blog posting, he didn't threaten the school, but merely informed them of the repeated breaches of the sites policies by one of their IP addresses (which is the usual policy, I guess). It's not clear how the confrontation between the "offender" and the headmaster went - perhaps he was just looking for a reason to quit? Perhaps the headmaster put a lot of pressure on him? I cannot tell from the posting. But all in all I think Mr. Greenbaum is the least to blame in this constellation.