I would say it was more the responsibility of the cashier not to sell to someone who is obviously drunk. In WA it is illegal to sell to a drunk person. It can be hard to tell if they are drunk though. When I was 18 I was a cashier at a convienience store and a group of women came in. One of them brought a bottle of beer to the counter but was short $1. When I told her she was short, the b**** slapped me! I took the bottle off the counter and she was just there staring at me like she wanted to kill me. Her friends were laughing about it but got her out of there after I told them to leave. I should have called the cops but I didn't.