Any shots fired there were not intended to hit the terrorist. Whether he fired back or not is hard to tell from video and audio that has been made available to the public. Looking at where the boat was relative to LEOs, any one of them could have hit the terrorist in the boat without much effort.
It would have been logical to try to drain out his ammo supply and see if he was in any condition to be firing back by some well placed harassing fire.
Riiiiighht. That’s why the boat is riddled with bullet holes. The only reason the punk survived is he was shielded by the engine.