Are we watching the same video? He waited untill the flags settled onto that slight turn right to left, (orange), and ran em.
The formula is brutally simple. You go to the line with a Rifle that has .150 agging capability, and trust it. Tony had probaly studied the conditions that morning and knew that there was that gentle angle as the condition would swing back around, and he knew how long it would stay there.
No adjustments, and certainly no magic. He knows when to shoot.
One think I really liked about that video was Tony's reaction. He has probably done this thousands of times, yet, when he looked after that last shot, it could have as easilly been the excitement of a first year shooter. It never gets old.
I suspect that is a Bartlien Barrel.