First of all, if you haven't already done so, create some guild rules. Get your officers' input in them, but you're going to have the final say. Post them in a place for the whole guild to read. Make sure any new recruits read them as well. This will eliminate 99.9% of any drama. If you already have rules, this might be a good time to take a look at them again. Did any of them get broken with no consequence? If so, rules that are not enforced are not going to do you any good.
Second. This officer you have is going through burn out. It's stressful having wipes and with his intensity already pegged, he's going to feel it more. That being said, you need to try to have another talk with him about what he's doing and how he's effecting the guild. Make sure you let him know that he's the one with the problem and it's up to him to fix it. Offer your support, but make it clear that he has a choice and you will do what is necessary.
Once the rest of your officers see that you are dealing with him, they will chill out.
And don't you think this officer is doing what he normally does by pushing your buttons or the collective guild's buttons? You don't think he's confined that behavior just to during raids do you?