I heard it was to draw fire AWAY from everyone else.
LaVoy did a good job of setting up a circular-firing squad scenario. The first shooter could have easily missed LaVoy and shot the agent in the tree line who cowardly delivered the final shot. That may be why the first shooter ran for cover behind the car, after taking the first shot. The cowardly tree-line shooter than moved right to remove the straight-line angle to the first shooter.