Sending you lots of love and support. <3 The process of leaving can be so difficult.
Tbh... who the heck knows what rock bottom is. I'm sure it varies from person to person, and equally I'm sure an individual can feel they hit rock bottom on more than one occasion. I wouldn't place a lot of weight on his insistence that he's hit rock bottom, since it's such a subjective concept that is apt to change at any time. I've always wondered (with a lot of anxiety and stress) over my AH's hypothetical rock bottom, as he hasn't seemed to hit it after years of really serious incidents related to his drinking. I'd not concern yourself with whether AH has truly struck that fabled point, and just concern yourself with your own health and wellbeing. Let him do him at this point, trust your instincts (and I swear we friends and family of alcoholics develop a sixth sense for this stuff that's borderline psychic), and take care of yourself.
Sending hugs your way. <3