Bomber on no-fly list on flight: Airline's fault?

The government says that the bomber who was on the no-fly list getting on a flight was effectively the airline's fault.

The policy requires airlines check every 24 hours for a new/updated list. This guy was a new addition, so he got missed. And they are now changing the policy to require airlines check for new/updated lists every two hours.

But is it ultimately the airline's responsibility? Isn't that what the TSA (Transportation Security Administration) is for? Every individual person goes through a security screening, and every individual person gets looked at by a TSA agent.

But the government says it's the private airline's fault, not the TSA that they oversee.