I know a couple of people who were alcoholics. Well, as they'll tell you, they still are; they just don't drink. They've always said they're only one drink away, but they've both been dry now for over 20 years.
It's true that alcoholism is a lifelong battle, but to take on such a cynical tone that one can never truly quit and "will be back" is really crappy. Hopefully he stays away from alcohol for the rest of his life.