I have known several alcoholics who have gotten DUI's and it was not rock bottom for any of them. Most are multiples now.
One guy has had 5 - YES 5!!! OMG. He still drinks - won't drive (as next one is habitual offender and serious time). But STILL DRINKING. I just don't get it.
Your husband's boundary is very manipulative to me seems to really be trying to diffuse the situation by controlling it all even telling YOU what to do if HE drinks.
If he starts getting angry with you "because you want to talk about it' and tells you you are overreacting or somehow its your fault (you let him drive right?) would be the classic next move.
Very sorry you are having to deal with this. Hope you go to al anon soon. I just started myself.