Several things SHOULD have marked Abdulmalallab as a potential threat. 1. paying cash for a one-way ticket. 2. amplified by having no luggage. 3. coupled with his age and sex. How these factors were masked. 1. purchase of the ticket in advance in Accra, Ghana. 2. then goes to Nigeria where he boards a flight to Amsterdam. 3. transfers to a flight on another airline (same ticket) in Amsterdam. Clearly the planning of the mission was far better than it's execution. The planners divorced the cash purchase from the actual departure location. The flight switch helps mask the lack of luggage. The planners introduced 'noise' into the situation which tended to separate and mask the flaming datums that should have set off alarms. Fortunately the kid was incompetent or his training deficient. This security failure involved multiple point failures by numerous governments, agencies and individuals. It was a system failure, not culpable negligence.
Obama visits Paris attack site, pays tribute to victims (AP)
from the article: Israeli firm blasted for letting would-be plane bomber slip through