Bingo.

"We're a government agency... we're not allowed to be wrong," so they'll bury their heads in the sand hoping it going away. They would REALLY risk spilling the whole can of beans over just saying "hey, listen, our oversight sucked and some guys got away with some pretty crooked sh*t. We're going to right the wrong, change some internal policies and move on."

Too proud to do the right thing, otherwise it would've already been done.