Totally OK.
FWIW, most people who get sober don't do it for a single reason. There may be a single incident that brings about the "moment of clarity"--in my case it was being so sick from withdrawals at work that I had to have someone drive me home. Was that single incident WHY I got sober? No--it was just one of the "nevers" that happened to open my eyes to the fact that my drinking was causing things to happen that I didn't believe could ever happen. It made me look at the OTHER things that were going south in a hurry.
So maybe this was his moment of clarity and he will now SEE (or at least see more clearly) the damage in other parts of his life, including his relationship. No guarantees, of course, but it certainly isn't out of the realm of possibility.
But it's just fine for you to stay out of it at this point.