Guy reactions are illogical. If I tell you I'm a killer, an ordinary persons gut would say disgust and contempt. But now I'll tell you I killed two people in defense of my best friend when he was getting attacked, you might feel a lot better.
Conversely if I said I killed in defense, you might first sing praises of me. But if you came across information that my killing wasn't necessary, that the attacker had already tried to flee or surrendered, you would be disgusted.
Conversely if I said I killed in defense, you might first sing praises of me. But if you came across information that my killing wasn't necessary, that the attacker had already tried to flee or surrendered, you would be disgusted.