Well, that is the inevitable result when a group of human beings presume to speak for God and attempt to coerce others into believing the same way they do.
If Paul Hill killed these people with the intention of "rendering justice," then you'd be right. If he did it with the intention of protecting lives, then "presuming to speak for God" was not necessarily a relevant issue.
Not to be unkind, but I'm not particularly interested in the thought processes of a murderer. My only concern is that murderers assume room temperature as soon as humanly possible.
If Paul Hill killed these people with the intention of "rendering justice," then you'd be right. If he did it with the intention of protecting lives, then "presuming to speak for God" was not necessarily a relevant issue.
His motivations are immaterial - his actions are what should be judged. And judged they were.