I personally think we need a lot more research before committing to taking a final legal stance on weed. We've got a plethora of uninformed opinion, hearsay, fear-mongering and misinformation on both sides, and not much else.
I'm personally fairly conflicted over it. Medicinal properties? Yes, but in a similarly limited fashion to natural opioids, and I don't think a whole lot of people want heroin legalized. On the other hand, we have fairly good evidence that it's less addictive than both alcohol and nicotine, and the intoxicating and detrimental health effects seem to be comparable to either or both of those two legal drugs. It's a toss up.
As far as this specific case goes, though, you have got to be so, so stupid to get into a car that has anywhere near that much controlled substance in it. Be it marijuana, cocaine, or prescription pills, you deserve what you get in 99% of the situations where you set foot in that car. Hope he can pull himself together, he's got the talent to be great.