If you look at you contract and say "But the customer didn't do that" three things: (1) if the contract is an ID/IQ, the customer technically didn't have to flow down 52.211-15 in full text because an ID/IQ does not bind a contractor to performance - check your task order though; (2) Mistakes of the CO do not absolve the contractor from public law compliance. Another example comes with the TINA series (52.215-11 through 15). If the CO mistakenly flows that into a contract, it's the obligation of the contractor to have it removed via negotiations.