Ultimately, it's up to the individual to police themselves in all situations, not just at a football game. I remembered when this happened and while it's an unfortunate event, it was his fault for drinking too much and then doing whatever he was doing near a creek and a 40 foot embankment. His decisions led him to that spot, not the Bills, drinking laws, etc.
If he doesn't get that drunk that day, he doesn't die. But it was his decision to get that drunk.