That is not correct.They primarily use "instinctive fire". This involves looking at the target, not looking at your sights.
The infamous "instinctive" ability to shoot proves to be an "instinct" not shared by the overwhelming majority of most shooters, which is why they train and use aimed fire techniques with both long arms and handguns alike.
See what you need to see to make the shot, and outside of spitting distance, most shooters need to see the sights. Even Delta guys.