Based on both my own experience and my experiences training experienced iron sight shooters transitioning to the dot at work, his statements in the video are exactly what they (and I) said before "getting over the hump." I literally used to be that guy and I know it when I hear it.
Speaking of that hump, based on both my own experiences training new shooters and those of three LE Academies I'm aware of, new shooters do not experience that hump and starting them on Dots followed by irons results in them becoming competent with irons faster as well. This mirrors the U.S. Army's experiences with Dots on carbines.