Is it not just a code error? Cant they fix it without taking the car apart? The Technician said the door panels etc would have to come off. 
They shouldn't need to touch the door cards. If one of the window regulators was acting up then perhaps as each motor has an electronic module which controls the soft stop and anti-trap. This is a 'global opening' issue as it affects all windows at the same time. There is a central module, and this fault can be casued by water ingress. (on some cars the windows open automatically in the event of the car turuning over in an accident)
TT's right about demanding a new module, as they're guaranteed to report no fault found when they investigate.
As a quick thought, you know pressing the open door button on the key fob for a few seconds will cause all the windows to open while the button's pressed? (and they'll close with the lock button) Is it possible that someone's done this accidently?
Also, were the doors unlocked and did the alarm go off?
