All I can think is that Breuer was on a CYA mission: Holder knew they were in hot water for doing this without Mexico's knowledge, so he sent Breuer to Mexico to get their approval after the fact.
Nice work by Sharyl Attkisson. She seems to have new stuff that even the gun blogs don't have.
Breuer was sent to find out what it would cost to get the Mex gov't to spin the part line.