Hmm....now you are contradicting yourself. Which is it....can you defend yourself...or not?You cannot beat his ass down unless he chases you off his property.
PS...he wasn't in his yard....it was his sister's.
Maybe he feared for his sister's life being threatened by the basketball.
Time will tell.
You cannot just go onto someones elses property. that is trespassing. You are breaking a law. If that person pulls out a knife and demands that you leave then you cannot assault that person. That is not self defense.
If you leave, or are attempting to leave and that person continues to chase you, and catches you, then you can legally defend yourself.
There is no contradiction there.
Note: I not defending an act by a mob, if that is the case, just giving some bait for catch.