Why do i lose honor for killing in self defence?

[JustYourAvarageEgg]

I got jumped by murfrees and i killed them all, after that a stranger started shooting at me for no reason, and when i killed him i lost honor, why did that happen?

[Kean_1]

I wouldn't read too much into it.  That kind of stuff can happen.  Your honor won't suffer much for it although you may have a bounty now in that region. 

Just pay it, kill a few birds, etc. and soon enough you'll be back to where you were.