Hard to decide if I was on a jury. He was coming out and not in the house. She was outside coming home. OTOH his relatives excuse for his burglary is funny.
Your difficulty is that you are thinking about legal versus just. The law says you can't shoot a thief if he is fleeing. At this point the law often serves as an impediment to justice and as a juror you should consider that. I believe the thief's life was forfeit to the homeowner the instant he entered without permission.
Police said they heard a loud confrontation. That’s enough for me. He wasn’t singing Happy Birthday to her.