The intelligence/security agencies would like the consular officials in Nigeria to take the fall for this.  The agencies seem to be telling journalists that the father's warning wasn't relayed to them with enough detail to justify putting Abdulmutallab on a no-fly or selectee list, so they just stuck him in the 550-thousand-name catchall database (known as TIDE, the Terrorist Identities Datamart Environment) rather than a more active 400-thousand-name database.  But neither database would have made him a automatic "selectee" for special screening (roughly 14 thousand people are on that list), let alone no-fly status (4 thousand).  And it's hard to imagine that even transmitting a full transcript of the father's warning would have boosted Abdulmutallab onto the selectee or no-fly list.

Why is it so hard to get on the selectee or no-fly lists?  In part because privacy campaigners have made the lists less effective and more controversial by raising phony privacy concerns -- and getting Congress to buy into those concerns.