Getting back to my question – "Why do it?" The obvious answer is that mounting a weapon on a Hummer was attention grabbing, fun, and similar to something East Coast Gun Sales saw in an action movie. There is no reason for ATF to license anyone to own this weapon for that type of application.
In rigging up this Hummer, East Coast Gun Sales installed this weapon in a manner not intended by the manufacturer and exposed Officer Kurty to significant risks that I suspect he did not understand. Although the officer was "was proficient in all types of firearms" there is little chance that he had a level of proficiency with this weapon to operate it safely and in full knowledge of all of it’s risks. I contend that in this application, only the designer/manufacturer and military personal trained to service this Gatling gun would understand all the safety measures needed to use it safely. I believe this lack of training and understanding removes Officer Kurty from the Darwin category.
For the sake of Officer Kurty’s widow and children, I hope East Coast Gun Sales has deep, deep pockets and a lot of insurance.