Bribery and corruption are rife within Egypt and I have seen it within aviation from airport security down to the airport check in staff. I myself was once stopped at Cairo and asked to pay a bribe to facilitate my passage through security and I was in full uniform and was just about to operate a flight.
Getting something airside at Sharm that should not have been will not have been rocket science. If these intelligence reports prove to be true, then I suspect this is a terrorist attack that has been carried out with incredible simplicity, that will leave many in bewilderment.
It's a toxic combination when you have an individual who is in a position of responsibility yet is poorly paid with mediocre training, along with a potential touch of religious empathy.
This is the scenario that I suspected from the start as soon as ISIS claimed responsibility, whilst many were still speculating on the feasibility of a surface to air attack.