He's already done both outpatient and inpatient, yet he makes the conscious choice to drink/use.
There isn't anything in a new inpatient that will be vastly different from the last one.
The man has been a drug counselor. He's knowledgeable enough about recovery to be dangerous to himself and others, those he would suck into his disease.
My best suggestion is to step back and watch from a distance. All indications from what you've describe tell me he's still playing with fire.
As a long-term recovering addict myself, I can assure you if someone is serious about recovery, they will go to any lengths to stay clean.