I have a lot of experience with dry drunks. They usually come crawling back to their former "support group" on the precipice of taking a drink, humbled to have discovered that a drunk without a drink and without a program is just a wet drunk waiting to re-emerge. Or, they come back too late, having succumbed to the unbearable torture of living without anesthesia and without the spiritual community that once enabled them to live unanesthetized.
I've been there more than a few times in the past several years of sobriety. The paradox of sobriety coupled with a "support group" is that it gives you back your strength and your confidence -- and you start thinking, "Maybe I can do this on my own, who needs those boring fucking meetings, who needs a spiritual roadmap, I can just live a normal life. I won't drink. Simple."
Trouble with that is, the confidence and strength that was being constantly renewed in the boring meetings is a well that needs constant refilling. Without the support of a group of peers, most alcoholics revert to old habits of thinking... which leads inevitably (sometimes quickly, sometimes slowly, always deceptively) to that sense of emptiness and acute sensitivity to the pain of living that drove us to drink alcoholically in the first place.
One of the most important aspects of sobriety, and a spiritual axiom, is the necessity for rigorous honesty in all one's affairs to maintain a sober life. Time and again it has been proven that if you quit drinking and fail to alter the rest of your character, you are merely postponing the inevitable. Only sociopaths can live with themselves as liars. Eventually anyone with even half a conscience becomes overwhelmed with guilt about their dishonesty -- and he drinks to drown out the conscience.
My guess: he's inches away from a drink -- or he already slipped and is lying to himself, telling himself he can handle it, and lying to everyone else.