Yes, it will be very interesting to see who was actually traveling on those stolen passports. They should also take a look at the ground crew; one of the most vulnerable points for any flight is when the luggage handlers are inside the aircraft loading “cleared” bags onto the jet. At that point—with the right people in the right places—it would be easy to put a bomb into or under screened luggage.
Very easy indeed, ground crews are a vulnerability worldwide.