beleive he responded the way he did (verbally) because of the history of fence line dispute. Had there not been that history I doubt it would have come to pushing/blows.
All that could be but while I know the area he lives in I don't know his neighbors. Guessing who started the fence dispute is like the chicken and the egg riddle.
I have only a passing acquaintance with Jim 45 years ago and a little interaction a few years ago on stuff pertaining to his lots. He never seemed like a hothead but neighbors can get under you skin and who knows what you get.
Bottom line, the neighbor pushing him is the act of assault that launched the blow. Boundary disputes can be solved without fistfights. Neighbors can talk. I think this hothead action tells a lot about the guy doing the pushing's communication skills.
A power saw at 7:00 may be rude but is not illegal. I am glad I am not in the neighborhood.