BrianWhitt: is this because they did so well when they started the round as a Hack they were given the Amateur status?
No, it's because they were doing well outside the tournament, elsewhere. So, they got promoted in tier. But, they continue playing from their original tees in their original tier if it's a tournament, and this discrepancy can last the whole month, if it's a monthly tournament. An imperfection in the current tournament system that WGT may address in future.