Two of the best guys I used to roll with liked to get high, both before and after practice. One was also a Greco Roman guy who used to love doing soft wrestling while high or after a few beers.
While we trained very seriously most of the time, we trained with a buzz on in so many living rooms, wedding receptions, parties, and parking lots I lost count. Oh the stories our loved ones could tell!!
I consider full contact jujutsu safer than aikido practice anyway. Why, because you're not giving away body parts or your whole frame to be thrown. Having someone fight to get you while you fight back is much safer, for me.
Anyway, while I don't smoke weed, I have trained/played with some veeery well known men while drunk.
and we had a blast. It's another way of testing to me. Then again, I've also trained weapons in a raging blizzard two feet deep and blowing sideways, outside up and down hills, at night by moonlight, I've also gone all out while drunk (with permission from my partners). It's fun to test and play.
So, while -in general- I am all for not allowing intoxication during training, I'm just not much for sweating the little things. I agree with Fred, that some of the worst examples of Budo I have ever met were very legalistic, and wound so tight you...well, that's for another day.