Shitty deal. I know how you feel, had a QP stolen from me years ago, but I didn't grow at the time, so I ended up owing money to my guy. You really can't trust anyone when it comes to weed and drugs. (notice how I seperate the two) People will do anything for their drug of choice, and to them, stealing is the best way to get drugs.
Will Karma catch up with him? Karma is a lot like religion: Hard to prove, and just as hard to disprove. Sometimes I ask myself, who's dose of Karma is this? Is this my bad karma catching up with me, or is this someone else gearing up for negative karma. Sometimes bad people do bad things to good people, and sometimes its the good people that have to do the bad things to the bad people. See how twisted and unpredictable karma is? It's just as bad of a school of thought as religion.