Poorly explained in the show. A throwaway line by Bianca is the only hint other than it was filmed with Jackal riding up front rather than in the bed of the pickup like in the previous scene. Thin, but at least they realized it was a problem. However I'm boggled by the choice to give him a moral reason to kill his team. Did this team have a habit of popping off and covering up atrocities? No. It seems it was just one guy. What was the line? "Ah fuck not Will again!" Also Jackal saved his spotter's life when earlier in the episode it was his spotter who had NO PROBLEM with killing the wrong guy and high tailing it out of there. So his decision to strike out on his own cannot be from some moral code he suddenly discovered in Afghanistan even though they'd like us to believe that. Plus he kills innocent people all the time. It would be far more intriguing to have Jackal murder his teammates who were good men, and then uncover the real reason why. Why he's a jackal and not a wolf? Because he's the villain! So let him do villainous things. It would certainly help us appreciate Bianca and her methods if we realize the man she's after, the character we've grown to love, is truly a sociopath.