@MMarciano,
Whether or not the victim had also been drinking is a side issue. If your friend had been sober when the accident occured, not panicked and called the police/ambulance right away this would have been a very different story. If you drink and drive, you've only got yourself to blame, and at 44 he doesn't even have the naivete of youth to excuse his actions.
Many years ago I was driving down an unlit country road in the dark having consumed a pint of beer. When I turned a corner, I came across someone walking down the middle of the road, dressed in black with his back to me. I saw him in time and swerved out of the way. Since then I don't drink anything at all and drive. Had I hit him, he would probably have been to blame, but the fact that I'd had a drink, even though I was well under the legal limit, would probably have resulted in me receiving some form of penalty. Now, if I'm going to have a drink, I walk, catch a taxi or a bus, or just stay in. It's just not worth the risk.