My first question is were the cops wearing their Official Police Uniforms or their fatigues or Ninja suits?
Police have good uniforms that are easily recognised as being Police uniforms. but many of them prefer coveralls and combat boots., Much like burglar might wear.
Are not ninja suits (with obligatory ski masks) Official Police Uniforms? Or Balaclavas?
This story is rather suspicious. I'd be asking why the cops really showed up at this guy's house. I suspect the cops aren't as cleancut as we'd like to think. Sorry, while 90 percent of the cops in America are law-abiding...10 percent aren't. We have reasons to maintain our security.
Even if they are in their uniforms, if it is dark and you don't have a flash light on them you would not know. All you would see is 2 guys holding flashlights directed at you (making it harder to see them) telling you to drop your gun while claiming to be cops. The guy may have had a small flashlight attached to his gun and was trying to put the flashlight on them to see if they are who they claimed to be.