Dude. There aren't that many clicks on a leupold scope, and the further you get from mechanical center (o,o, on the crosshairs) the greater the cumulative error from adjustment.
His training got him close, but I promise you, that shot was all shooter.
The Army usually zeros there's out to 300 m while the Marines zero there's out to 700 m. This guys is a country boy from Alabama and probably has worked it up for a long range zero, say 500-700 m plus.