7500 signal...landing in Canandian airspace...still squaking 7500 hijacking code...
that's odd... still squawking the code, but in contact with ground saying all is well. That's odd.
As a former air traffic controller, I know the first thing the controller does, is tell the pilot he is squawking 7500, is this intentional? The possible problem may be, if there is a hijacker in the cockpit, he may know exactly what 7500 means, and may force the pilot to say it is a mistake.