My thoughts. I would not have a problem with a shooter re-obtaining his weapon or needing to keep him covered. He or I would not be capable of such movement. Unless zombies where here and one of us turned.
Regarding cops, I would have mine out of view or reholstered and follow their instructions, replying for them to stand down, shooter is neutralized, in exactly those words. Cop buddy said they were good words to use. Giving further details to the first guy who asked for them.
As far as "black" guns, most depts do nowadays use the plastic fantastic junk so by choice I guess they win on that aspect. My EDC is a satin finish stainless steel, no not plastic, and I will not swing that way. I am a straight steel guy.
Nemo