If they didn't put that in, what would stop a less-than-honorable supplier from low-balling the contract, using rodent-infested wheat, and then suing the DoD wh

If they didn't put that in, what would stop a less-than-honorable supplier from low-balling the contract, using rodent-infested wheat, and then suing the DoD when they get their contract canceled because someone finds rat feces in their brownie? Or more broadly, what would allow the DoD to cancel that contract in the first place in that example, if the specs didn't say they had to be free of the stuff?