I am going to have to call B.S. on this video for the plain and simple fact that there is no aiming device, like a camera, mounted on that pistol or on the drone itself that I can see. And as you pointed out, there is no actual footage from the drone showing it shooting something. Could this be done? Yep. Entirely possible. And like the printed gun, some idiot will do it for real and post actual video of it being done.