Its not exactly the same issue but I find that sometimes Delta partner airlines offer seats on Delta international flights cheaper than Delta offers them. When I booked Business class a couple of times through Air France that were actually seats on a Delta plane, I asked Delta why the seats were cheaper through AF. I was told that they award a certain number of seats to their airline partners and those partners can sell those seats for anything they want and often they just want to get rid of them. Maybe it works the same way with award seats?