Does Arkansas have any laws pertaining to stand your ground? If so, castle doctrine would be a moot point.
As far as the don't mess with a woman who is in a relationship. 3 people acted like fools. The man messing with a woman in an obviously committed relationship, the woman, messing around outside of her very committed relationship, and the man who stayed with the woman who messed around outside of their very committed relationship and went looking for a fight to preserve her honor (or his own)
A man who has a beef with me chases me through town, stops his car a few feet from mine and charges me obviously intends to do great bodily harm. If my gun was holstered when he was pulling up, it isn't when he leaps out.