I don't mean to hijack this thread but from my understanding of the disease, a slip or relapse happens usually well before someone picks up. Blaming a fight with his girlfriend is just an excuse. She didn't cause it, she can't control it and she can't cure it.
I am sorry but I am really triggered that she has become the scapegoat. I am the wife of an addict and has blamed before. Sadly, I believed it. There will always be an excuse, if someone doesn't really commit to being clean and sober.