According to documentary evidence written in several books on Hardin (Wes, not gunkid), NONE were shot in the back. These are from court records, no less. Even the deputy Wes shot, shot Hardin in the back FIRST, without warning, and Wes swung around and shot him in the head.
There was a feud going after the Civil War and Wes was caught in the middle of it. Notice Wes was PARDONED by the govener of Texas after 18 years in prison (where, unlike gunkid, he got an education as a lawyer.) Pardoning is not something done to a backshooting murder.
I think gunkid's thinking more along the line of Billy The Kid (now there you see the name 'kid' shows up.) The Kid was a pure punk slime who did shoot people in the back.