I'm in my early 20s.
Look, it's unfortunate it happened. However, the law in the state where the person got the bartending job had this law on the books. That means the bartender needs to be aware of all of the liability issues that come along with being a bartender in the state of Missouri.
I think at the very least, if you are going to continue serving the alcohol to someone who is already intoxicated (which, I hear, is the main crux of the law in Missouri), then you have to try to make sure the guy doesn't get behind the wheel of the car. Getting drunk to the point where you are twice the legal limit and then being allowed to drive behind the wheel of a car is irresponsible. Mostly due to Hancock, but I do feel some blame needs to be placed on the bartender simply because of the explicit legislation in Missouri.
I assume you bartend in NY, and I don't know of any laws that would give the bartender liability like that so I won't comment.