i guess i agree with outtolunch here.
i get what you are trying to do, but it sounds - for one, complicated: how do you know this friend is soon to have the potential to be under the influence? i mean, do you have to assess where he is, what money he's spending, who he's with, look at his pupils.....
for two, crazy-making: see number one.
for three, controlling.
i understand having a good, good friend who is an addict. and....easy for me to say..... but i think if we are going to choose to be in relationship with a non-recovering addict, well then we are going to be around their addict crapola. it just comes with the territory.
he was being manipulative and acting like he didn't get it, on the night of the concert. but, again, that just comes with the territory. it's like us expecting a five-year-old to behave like a 20-year-old. he simply cannot.