I totally disagree. Homeowner told belligerent ex to leave the property. He refused. Homeowner retrieved firearm, and belligerent ex closed on him, pushed against him and tried to grab the gun AFTER A WARNING SHOT WAS FIRED. There is a significant disparity of size and force between the two.
Actions have consequences. I’d vote to acquit.
The shooter didn’t own the place, it was his girlfriends. He wasn’t the ‘homeowner’. I don’t know how much that complicates everything, especially when it was a agreed upon location and time to pick up his child.
I wouldn’t charge the boyfriend, I would charge the wife for manslaughter for if she had not reneged on a legal order, the husband would not have been killed. I think a case could be made for it.