Yeah, I don't dispute this. What my drawing shows is that it's possible for the sun to backlight a contrail at sunset, and this doesn't disagree with that. Finny seemed to be saying that the contrail had to be lit from underneath and my drawing shows that that isn't true.
Here is a what I said a couple posts later:
The viewer on the ground will of course see the underside of the contrail. My point, which I think my drawing gets across pretty clearly, is that it's possible for a contrail to be lit from behind by the sun. To be honest, it's hard to tell exactly how the light is hitting it since it's coming in at such a grazing angle. It's either from slightly above or from slightly below, but mostly it's from "end on" -- i.e. in a direction running almost parallel to its length. It also appears to be getting light on its northern flank in some pics.
Not at that particular hour which is exactly when the video and pics were taken. The sunlight can't be both above and below an airplane contrail.