That is a tough debate really.
The man that was DUI was drunk, he had no idea what he was doing, apart from the driving part, while the innocent driver was innocent and sober, but was in an accident, and was killed.
The man DUI will have the excuse of him being drunk and not knowing what he was doing to back him up, so he will probably get a smaller punishment than what he should have.
I think that they should punish the DUI, but make it law that if he goes into a bar, or buys liquor without anyone, he gets jailed. Keep him alive to feel the agony of knowing that he had caused a death to an innocent person.