Talked with a guy I know in the gun biz, who shoots some competition. I was impressed with the Engelbert handled his weapon. He agreed, but he knew more than I did. He talked about the Vortex 1-6 on the officer's AR not being department issue, but how well he handled the site and how the officer worked the blind corners and rooms.
He said that speaks to two things...
Engelbert took the money and time to buy a good site ( the Vortex is not department issue)and get really good with it, along with superior gun handling. Especially under high stress. Even though he shoots an AR in competition, he said there's no way he could have kept up with the officer, as fast as he was scanning and clearing rooms.