The whole story he told you sounds like BS too me. An excuse. Even the laced story sounds like BS. If he wants to quit he will quit. If he cant quit but really wants too he will put him self in to rehab, him self. I think hes just giving you lip service, too keep you off his back.
Wheres this dealer sell'en weed with crack in it, sell'en it for the same price as weed, so peeps don't know he laced it. Sounds like a hell of a deal, and it will only keep working if he keeps putting the crack in the weed, at a $loss$ of course.