Although the young vermin deserved a lesson that they would never forget, ultimatly you would have been on the loosing end since eminent thread to your life and to his could not be established. It is sometimes shocking how the so called victim could turn villian. He could have been related to them and it could have been a drunken brawl and upon being sober he could have easily turned on you in a civil proceeding or furthermore in a civil proceeding as far as a judgement against you where eminent threat to life and limb could not be established for certain. It is difficult to sometimes drawn the line where eminent threat to you and to others stops and starts, but I would have called lawenforcement from my cell phone, of course the response time would have already been too late, but its one of those judgement calls that is very tough. If they were stabbing him, would you have acted differently, where does the line start and stop, fists are deadly weapons also, especially in those who know how to use them, so its a very ,very gray area, this is the very reason why I avoid fairs, games, carnivals, and other places where alcohol and hooliganism in crowds can breed this type of activity. Hopefully everyone came out ok, but rest assured the hooligans will one day come up against someone like Vincent from the movie Collateral and they will learn a PERMANENT lesson that they will never forget, unfortunatly I prefer to side on the side of caution due to the civil litigation being a reality that I have seen all too often favor the vilian, but I rest content that people prone to this type of activity have their life expectancy cut severly. I know some people who would have followed them after the fight was over and took them out one by one, etc. Thats not my thing, but like I said, they will come in contact with someone who will make them regret being born. .