Why do people assume that because someone had alot to drink one night they are diseased alcoholics? Maybe they guy doesn't drink very often. We have all been in the bar on an overnight and taken a look at the clock before deciding whether to order another or not. If you are buzzed and /or getting close to your companies cut off time (or 8 hrs), then order another, of course that's poor judgement. The same goes for these A holes that get lit up at the bar and decide to drive home.
I can't imagine how bad this guy feels right now, but he screwed up and that sucks, be we all know the rules.