Personally I believe you are confusing idiocy with intent.
You want to write it off to idiocy you go right ahead.
I don’t write it off to idiocy.
I believe their intent was so the terrorist attacks wouldn’t be stopped and they are now trying to created some defense to explain it.
I believe that’s exactly why they came up with the “spontaneous” lie. That being there is little or no planning for the attacks so there is no way to pick up on what the terrorist are up to before the attack takes place.
I think that is butt-covering for not catching them when the bread crumbs were laid out for them by the Russians.