First, it was probably not TSA, but a private contractor that examined your ID, so in this case you really can't blame the TSA.

Of course the TSA is at fault, as the contractor would be operating under a contract from the TSA. The TSA is ultimatley accountable for the performance of thier subcontractors.

When CO loses your luggage, even though the majority of it's baggage handling is contracted out, CO is still accountable. Exact same thing here.