When someone has to start using the vague, unscientific concept of "human nature" to prove a point while debating a serious matter, and it's the best he can do, that's pretty indicative that he really means "according to my opinion and biases."
There are two areas of science at work here -- the first is optics -- the basic skill of aiming. The second is psychology -- especially the reaction of people under great stress.
Now, I'm not a cop. I've never been in a shoot-out as a civilian. I have, however, been in combat, and have used a handgun twice (successfully) under stress. I have also spent many years training men for combat.
1. Optics: The key to understanding the proper use of the front sight is distingushing between
sight alignment (the relationship of the sights to each other) and
sight picture (the relationship of the sights to the target.)
Small errors in sight alignment add up to big misses at the target -- the sights are so close together that a small displacement of the front sight in relation to the rear sight is multiplied many times, even at short ranges. Consequently,
sight alignment is more important than sight picture.
And it is definitely possible to keep the sights in view -- a good exercise is to use a .22 cal conversion kit (mine is a Colt Service Ace) and track the sights throughout a multi-shot engagement cycle, so that the sights are aligned before the gun returns on target from recoil. From that point, progress to moving and firing.
Now, this doesn't mean you have to have a
perfect sight picture in a short-range, fast-moving situation. You just have to have one that's
good enough. There are techniques to do this -- the "flash frontsight" approach, for example, the hold under technique, and so on.
2. Psychology under stress: The key factor here is
perceptual narrowing. Under great stress you will develop something like tunnel vision -- things outside your immediate environment will not be perceived. Your perception of time and space will change (for example, flight simulators for Naval Aviators have to have a special long, narrow carrier in their data base -- because when an aviator makes a carrier landing, the carrier
looks much longer and narrower than it really is.)
You also want time to
strrrretchhh out (tardykinesia), not speed up (tachykinesia.) After a very stressful experience (say an automobile accident) you will hear people say, "It seemed like everything was happening at once" (bad!) Or, "Everything seemed to be happening in slow motion" (good.) With practice, you can induce tardykinesia.
The trick is, through training, to make these psychological phenomina work
for you, not
against you. You want your "tunnel vision" to include the important things and disregard the unimportant things -- and under those circumstances you can do things you ordinarily could not do -- like track your frontsight while keeping aware of your enemy and the tactical situation -- because the perceptual narrowing concentrates all your mental abilities on specific things.
The contention is whether it is possible and optimal to use the front sight and make good hits under stress for a civilian, with proper training. The answer is, yes, it's possible.
Absolutely.