It's a tough call when you only have a partial story. It is unlikely if the chicken owner is justified that we will ever hear about it.
silkie, I understand you wanting to see the dog owner's side also. I'm sure many of us have dogs as well as chickens. I don't know about anyone else but if I was out with my dog and she ran off, harassed someone's livestock and was shot, I would feel the need to apologize to the person who did the shooting. It would be my fault for putting my dog in that position. I would still feel sad at losing her, but I would also have to kick myself in the hiney for causing it.
silkie, I understand you wanting to see the dog owner's side also. I'm sure many of us have dogs as well as chickens. I don't know about anyone else but if I was out with my dog and she ran off, harassed someone's livestock and was shot, I would feel the need to apologize to the person who did the shooting. It would be my fault for putting my dog in that position. I would still feel sad at losing her, but I would also have to kick myself in the hiney for causing it.