I figured he was mad because he didn't get any of the loot even though plenty of us didn't get anything out of there so he tried to get some people killed. First, he pulled me aside (not far enough away to where you couldn't hear him) and said that the random dude we encountered killed him earlier and wanted me to kill the guy for him which I said I follow the group and don't plan on starting anything. So while you guys were chasing him away, he then said that Hidden just killed a guy so we needed to kill him right away so he shot him.
I called him out and said we were all from GAF and then he got a swift arrow to the face as he asked for food...lol.
It really made no sense considering he happened to stumble across a good group, but I guess he wanted the loot for himself. If I had more than 2 rounds for my 1911, I would have executed him with style.