that sucks. but he probably would have tried other drugs whether or not you got him to smoke pot with you. (I'm a strong believer in people die when its their time whether it looks like a mistake from an outsiders view (doesn't make it any easier but it helps me make sense of tragic deaths)There's nothing anyone can do at this point, but yea it sucks when someone young dies makes you realize you aren't as invincible as you thought and you need to be careful.

I'm sorry about your friend hope you feel better.