the failure would be pretty large from what i can see. I'd have expected this to be caught when the individual initially decided to purchase the ticket, that ticket should have been printed with extra security screening written in bold face lettering, only to allow the person to have the ID crosschecked at security to see if the individual was who they say they are. Getting on the plane is about the LAST line of defense. We can say the "crew" is the last line of defense with FFDO, but that only works in a specific scenario. It will prevent another 9/11, but expecting a pilot to be john wayne and go back into the cabin to inspect the situation, inflight, or defuse the situation in the case of the african bomber, is dreamy at best.