First off, i have no clue what has happened here
But as a user who have moderated several forums over the past 15 years, some with some very heavy debates and attacks going on, my suggestion is to let people discuss it and be open but firm. That is, if you decide to ban a user, make it public (if someone asks) why the ban was set and stick to it. People will always nag and debate and you will have a hell of a time trying to delete all posts in the subject, try to defend yourself from censorship & dictatorship accusations and so on. In the end, it is usually much easier to just say "We made a decision, this is it. He did this and that and we feel that was warranted." instead of trying to quiet it down.
Having said that, something people generally wants to talk about is "freedom of speech". This actually only applies to public forums... this is a private one =)
*EDIT*. and i didn't see Justins post when i wrote this. Better to wait until the boss is home
Oh well, hope it all sorts out.
/HuBBa