Was there any reason for the guy to feel that she and her possible accomplices were preparing to invade his house? How many accomplices might have been hiding behind bushes, or even already at his back door?
Happened in the height of the riots and bolshevik home invasions last summer, right about the time when 3 cities had multi-block areas declare they were leaving the US and beatings were being down left and right... I think the argument could be made, yeah. Especially depending on what she said to him and how she was dressed at the time.
Totally random example.
You hang your bandana out on the closeline to dry. Dude shows up on your lawn in the dead of night to tear it down, you confront him, and he starts screaming "You Bloods need to get out of this neighborhood, homie. I'm a muffuggin' Crip and we gon fugg you up, homes!" - he happens to be wearing a different color bandana around his head (and jorts with high socks or whatever). That person has told you verbally, and with their mode of dress insinuated, that they are part of a large, active, violent group, which is widely known for regularly/currently attacking people. A reasonable person thinks "this is a member of a gang which is known to be violent, there are likely more of them, they have invaded my property and robbed me, I am afraid for my life".
Now let's say it's a Gadsden flag, or a Threeper flag, or a in this case a Nazi flag (which is agreed by all to be stupid) and it's hanging off your house. Lady shows up on your lawn in the dead of night to tear it down, you confront her, she screams "Bash the fash, get the f*** out of our neighborhood you white supremacist bigoted CIS male! I'm a certified anti-fascist and you are going to hell!" - and she happens to be wearing a black hoodie with a bandana over her face (and what, skinny black jeans and Doc Martens?). This person has told you verbally, and with their mode of dress insinuated, that they are part of a large, active, violent group which is widely known for regularly/currently attacking people. A reasonable person thinks "this is a member of a terror group which is known to be violent, there are likely more of them, they have invaded my property and robbed me, I am afraid for my life".
Thankfully, detestable as they are, Nazis are NOT known to be actively/regularly/currently attacking people - at least
outside of prison, and not to random people. Also this idiot hung his moron-warning on his own property, and didn't feel the need to vandalize or burglarize anyone on their property or instigate anything. I'd also point out this woman was not shot in the back, but the side or front, and she started all of this with other people present (if not on the lawn right next to her). Spitballing here, but they might have been a crowd of shadowy figures on, or at the edge of the property where she committed her crime and instigated the incident. They may have even been verbally involved (again, spitballing).
He "fired without warning as she was running away" - why was she running then? Was she even running, or just according to her / her friends? How'd she get hit in the front or side, then? She was found with a bunch of people in a ditch, getting first aid. Were they in the ditch while she was shot? Was that ditch on his property, or on the edge of it? Did he call the police, or did she? I'd give big money to hear the 911 call, if it was him. Or her for that matter.