From what you said, someone in your alliance actually provoked it by attacking a valley. Then again, responding to an attack on a valley by cussing people out in mails is a pretty dumb thing to do. I also have had at least half a dozen alliances attack my alliance members without provocation and then send us whiny mail that we are bullies when we hit all their nearby towns in response, so bleh. I firmly have no strong opinion on the matter whatsoever.