if he did it once, it will happen again.

you were both intoxicated. doesn't matter if you drink every night or once every 16 years.
you were driving while intoxicated.
no seatbelts.

you were a danger to others. period.
you got in a car with a driver who you said drank more then they should have...you were supposed to be the designated driver. call a cab. tell the bartender to take his keys. or call pd if he is too drunk to drive.

clearly no one was thinking responsibly..hate to be brutal but you made errors too.

get out of the relationship if you are smart.