From what I've learned over the years is what he's going through and feeling likely stems from a childhood/past trauma. What he went thru was probably a very real thing and his feelings are fully justifiable to what happened.

The hard part is when the "trigger" happens, any similar situation that brings up memories of the past trauma and thus triggers a defensive mechanism to keep himself "safe" from the abuse. Usually until they themselves come out of it, all they'll see is the past abuse/trauma no matter what you say or do. On occasion they might snap out of it sooner/faster/etc, but it depends on how strong the dissociating is at that time.

After 9 years the therapy's we've tried have been misdirected and wrong I'm afraid. Yer best bet at this point is to let him know that he's not alone, it's not his fault for what happened in the past, and his anger/feelings for what did happen is truly understandable. What needs to be worked on is him getting to the point where he can be around or see a similar situation as the past trauma, but to know the he's safe and doesn't have to react the same way anymore.

If ya haven't had any luck with his doctor getting referrals and the like ya might consider trying a community crisis line as there's many 24 hour ones out there. Explain to them what the situation is and they'll either be able to offer you the right help or know where you guys need to go.

-Gil