This guy did a few very stupid things. He showed a weapon before one was, strictly speaking, necessary, hoping it would talk for him, thus telegraphing fear. He fired 4 “warning” shots into the ground after being challenged by a punk who correctly assessed that he was afraid of using the gun. He fired a shot into the air.
Guns are very serious things; when a man points one he ought to mean it. Guns aren’t made for negotiation.
Dunno about that. Did they get off his lawn and leave him and his family alone?
That was what he was trying to accomplish, wasn't it?
No one died. No one was hurt. They left him alone. Seems like an effective negotiation strategy to me.
And in general ... if your house is being surrounded by 10-20 gang members, the last thing you want to do is to attract their attention in a hostile way. It might be a manly thing to do, but tactically it is unwise. Most likely they don't even know or care about your existence. You gain nothing by revealing yourself and your capabilities. Negotiations with gangs are unlikely anyway; the only people you can negotiate with are probably nice enough that you don't need to.
So from my "monday morning quarterback" POV, the best plan of action for him would be to call the police, then to hunker down at the house, distribute weapons and ammo to all able family members and allocate them to cover doors and windows. If any of these entry points is breached by criminals then the defenders have clear legal right to use deadly force.