Just something to think about...
Think back to the times when you've done rapid fire on a single target. Do you remember every sight picture? I'm not saying that you don't use it for every shot, I'm saying that at least for me, there can be perceptual distortions, and while all the shots go where you want them, you don't always remember seeing the sight picture crisp and clear. That's where muscle memory comes in. Don't forget, if you get into the realm of psychobabble, that your mind can only concentrate on one thing at a time, and it only has 7 "chunks" of short term memory space. Things can get left out, when you put together whatever it was you were doing.
Case in point:
I was in England with my wife on Guy Fawkes day. As we were walking down a London street, I heard a distinct double-tap. Before I knew what I was doing, I was halfway to the ground using a car for cover, and dragging my wife with me. On my way to a crouch, I looked up and saw the two flashes of light from the "double-tap". Before I fully proned out, I realized that I had heard a couple of firecrackers, and straightened up. Now that is the way I remembered and told the story for two years, when all of a sudden I realized that there was no way it could have happened the way I recalled it. Anyone with elementary school physics can tell you that light travels faster than sound, so there was no way that I could have heard the bangs and then seen the flashes. Ashamed I am that it took me two years to figure out that I was a victim of a perceptual distortion. (Now if we could just find a way to outlaw them.)
It wouldn't surprise me if some of the shooters are simply explaining what they perceived. I've known and been taught by some excellent shooters in the SpecOps community, and they've never mentioned anything like Ocular Memory Shooting; those guys are Master of the basics.
Chuck