sometimes the pads CAN just "slide off" especially if it is heat damaged, and this may be easier than you think. If one of the chips goes faulty, and starts drawing excessive current, it could heat up the contact, and soften the glue which holds the copper to the board. It then takes very little force to have to contact break away. And it could even have come off from removing the module, after a fault had developed.
You have to remember the way these are manufactured. The PCB comes with a solid layer of copper, which is then etched away in a pre-defined pattern, determined by a photo-sensitive layer which is exposed to UV through a schematic of the track layout. All those pads you see were once a solid layer of copper, and all the gaps have been etched out. Once it's been etched, they can become very fragile, and are only as good as the glue that holds the copper to the board, and the external forces acting on it. It actually doesn't take a lot of force to lift a pad, and any heat just makes that even easier.
You can actually get repair kits to repair pads if your keen enough!
This doesn't guarantee that the module would work after though, as it may be a problem with one of the chips rather than just the board causing your problem.
Anyway, I'm sorry to hear about your hassles,sometimes we all get stung now and again.