I see where he's coming from; if someone takes from you, and you didn't want them to (99/100 times, you likely wouldn't want this to happen), you might ask them to stop and give back what they took; they neither give back what they took and threaten you with violence if you try to stop them. So of course, if they resort to violence, one must use self-defense to protect themselves and their assets, which may result in the death of the person representing the violent entity. If we can't justify self-defense against any violent force, we're truly screwed.
I also see where the FSP board is coming from; they're the Davids standing up to Goliath, and the last thing you really want to do is piss off Goliath before you're ready for the final blow. FSP will do everything possible not to anger their overlords, which includes shutting its own members up or removing them from affiliation. They've already been referred to, mistakenly, as domestic terrorists, and I believe they still make the cut (among various, almost unrelated and benign people), and so the last thing they would want is to appear as though they advocate terrorism, which is a very touchy subject; you can get blown to bits for even being suspected of terrorism, nowadays. I mean, unless you're the guys who own the military, anyhow.
I wish I could write something here that would rationalize this one way or another, but this is just the state of the nation ATM; they're both right to do and say what they did.