You know, Barney, after a bit of thinking I have to conclude that your afterglow argument doesn't make much sense in view of the actual experimental result. If it were afterglow, then the leading edge of the trace would be smeared out, while the trailing relatively sharp. In the matter of facts it is the other way around -- the LEADING (left) edge is sharp, the trailing smeared out. I thus maintain that the fastest speed, at least in my case, was 0.2ms, whereas further dimming is a different effect. Perhaps the same applies in your case, when shooting TV screen.
