Could this be a reason why he is seeing daylight so soon?
The jury was outraged at the sentence that was given to him. They thought it was far too severe. He has served much more time in jail than many who committed much nastier crimes.
Dallas had a reputation in the community as a man of integrity who could be counted on to do his job. Pogue had a reputation of someone who tended to ride a little roughshod over the people he confronted.
I worked with game wardens in two states, and was one for a while, and in my experience, they, as a group, were more unreasonable and obsessed with their "power" than most other peace officers.
Dallas wasn't willing to leave his animals without making arrangements, and was willing to give his word to turn himself in if he were just given a little time to make arrangements.
It was a tragedy all around, that could have been averted if either one of the parties involved had been willing to bend a little more.
From reading about the incident, my speculation is that the actual shooting occurred when Pogue noticed that Dallas was wearing a pistol, and quick drew his own in a panic. Then Dallas thought he was going to be shot, and drew his own weapon. He was just a faster and better shot than the wardens.