The men in my family have done a few stupid things when drunk (my Uncle was once arrested at 2.00 in the morning, swinging through trees in Kettering, pretending to be Tarzan, and my Dad once cleared a cup-laden table on a station platform in the middle of the night). But the worst they've ever done in the house is to fall asleep on the sofa, sing too loudly, talk too much or throw up in the bathroom. And boy, have they known about it afterwards, because the women just won't put up with it. We give them hell over it and that's why they don't do it very often.
So you give this guy hell, and you also give your partner a good roasting over bringing him home in that state and forbid him to do so again. After all, you'd both do the same if your daughter brought home someone as bad in a few years. And if your partner's concerned about his mate getting home safely then tell him to go and stay with him!