Guys stop the Bomb theory stuff it doesn't make sense.
If the bad guys were to smuggle a bomb on board don't think they would have chosen a larger target than a Airbus A321?
Plus, bomb residue would have been ruled out from simple lab tests or Bomb dogs.
It simply make no sense. Of course the bad guys will take responsibility for the the terrorist act. Even when they have no idea what they are taking credit for.
Stick with the the structural facts. There's nothing to be gained from any of this