They just didn't get the desired result. You can't have that many breaches of security occur within what was supposed to be a controlled area, in such a short period of time, and not realize it was deliberate. Because if your theory isn't true, it means that the "greatest country in the world" is staffed by the Dumbest People in the World" (and that, of course, could never be true).
"Because if your theory isn't true, it means that the "greatest country in the world" is staffed by the Dumbest People in the World" (and that, of course, could never be true)."
Unfortunately, there's being plain, old incompetent dumb, and being deliberately-on-purpose dumb. I'm going with the second.