hi serene-
alcholics can not control their drinking. he is still in denial and thinks he can.
in AA, if he said the same thing to those gathered there, in my meeting at least, they would encourage him to go and try to control his drinking and that he would be welcomed back if he discovered he couldn't.
no one there would waste time trying to explain "controlled drinking" to him because really, most people only learn from their own experiences.
he's not quitting. that's really all you need to know. in all liklihood, it will creep back up from 5% to 20% to all out binge quite quickly. plus, he could be lying about it too.
naive