The REALITY is that every single one of us has a "line" - it's different for every person, but like it or not, deny it or not -
every single one of us has a "line", and if you push a person across their "line", they
WILL SNAP.
That Excuses NOTHING. It doesn't mean its OK to "Snap" or that anyone should get a "pass" for violence EVER. But it is a plain fact of human nature. Even the most patient soul can be pushed to the brink, if they are provoked hard enough, for long enough.
Remember that "Fan" is short for FANATIC. I didn't know the deceased, and I have no personal knowledge of him. Maybe he was just a fun loving guy who enjoyed a good joke. Maybe the Neighbor who murdered him is the only nut job in that equation.... Only two people really know for sure, and one of them is now dead.
But based on the NOLA.com report, well.......
http://www.nola.com/crime/index.ssf/2018/05/lee_big_lee_martin_shot_dead_a.html