Great episode.  A morality play with an excellent twist ending, properly foreshadowed.  I will say this about the morality play, however.  Although it seems like sound moral advice to "be a man" and to "take your medicine," any defense attorney will tell you that you're nuts if you take that attitude with the legal system.  The prisons are filled with people serving large sentences for minor crimes because they wanted to "do the right thing."  It was dark; it was rainy; he didn't see the old man; he just thinks he hit "something."  How many other cars were on the road?  Was it the accident that killed him, or was it alcohol poisoning?  Why sign a confession if you're not even sure what happened!  Morality/crime drama; no supernatural elements.