Pullum didn't shoot the other guy because of a traffic violation, he shot him because he was shot at. (Maybe you guys covered this already)

Looking at the story we have, Sounds a lot like Taylor got a bee in his bonnet and started every 'step-up.' From my POV, Pullum's final action was protecting his family. Granted, stupid all-round, but at this point I have more sympathy for Pullum and his family than Taylor.