When Capt. Bardow is pleading with Tilley, he tells him that there are 32 human beings on board the airplane. In fact, there are only 30 people on board the plane, 8 members of the flight team (captain, co-pilot, engineer, navigator, radio man, stewardess, steward, and bartender/purser) and 22 others.
Passengers are seen boarding an aircraft with tail number (registration) G-AOYM (Golf Alpha Oscar Yankee Mike). But when the captain calls air traffic control for taxi clearance, he uses callsign Macair (name of the airline) Golf Alpha Juliet Oscar Romeo, which would be for a tail number G-AJOR.
when the plane is first starting to taxi from the cockpit it is turning left as seen by the buildings going by the window. From the outside the aircraft is turning right.
On the aircraft the passengers go down a staircase to the 'lounge', where there is a row of windows the same as on the upper level. However, on the exterior shots of the plane there is quite obviously only one row of windows - so there is no lower level accessible to the passengers.
It is not possible to attach anything to the underside of the wing by suckers that would survive being blown off by the force of the wind flowing under the wing.
Such an aircraft suffering a catastrophic decompression would not suddenly dive out of control. The pilot would deliberately place it in a shallower spiral descent, to increase cabin pressure and temperature, while maintaining a sense of gravity. To avoid the need for oxygen masks, an altitude of less than 10,000 feet would be required.
It is unrealistic to suggest that Tilley could have attached a bomb to the underside of the aircraft wing without being seen by ground crew, flight crew or other passengers. Apart from which the underside of the wing on the Tupolev would be too high to reach without a step or platform.
Given the seriousness of the situation, the pilot would almost certainly have diverted to a nearer airport than New York - Gander, Halifax etc.