Meh, I don't believe this story, but even if it's true you should have called the police you handicap.
Excuse me, but if this friend has been giving me bullstuff and he comes on my property to do so, I have the right to do what I did, no police involved.
Well to be quite honest you could have shot your gun up in the air or something rather then at him. Even though if you did shoot him you'd still be in your rights to do so.
If he comes back with a knife now, I'll have a knife, a gun, and a club all in one, and he'll have what, a swiss army knife that's two inches long?