Bad guy dead.
Message sent.
I can’t think of anything wrong here.
Agreed.
He held out his sword in self defense.
The culprit attacked him anyway.
What is he supposed to do, let the culprit stab him with a knife so he can bleed to death too?
If the culprit did not attack him, the culprit would not have died.
The culprit is dead and the victim lives. That is true justice.