Drink Driving and who's responsible?

I read an article where a drunk driver and three friends were killed in an accident caused by the driver.
Now i am aware that driving while drunk does cause fatalities but who is responsible?
The driver is four times the legal limit when he/she gets in the car,the friends protest that the person is too drunk to drive but the driver insists that alls ok and not to worry.
The friends then decide to get in the car which i feel only serves to condone the drivers actions.
Further down the road an accident occurs killing all but one occupant of the vehicle.
Should the survivor be held someway responsible for not doing all in their power to stop the driver?
You may say that having lost friends in a crash is punnishment enough but i say they have aided the driver by their actions.
Thoughts please.