You sure about that? Read up about ghost-shifts in semiconductor fabs. Bunnie tells a bit of the tale in his story about counterfeit SD cards:
"Very low serial numbers, like very low MAC ID addresses, are a hallmark of the “ghost shift”, i.e. the shift that happens very late at night when a rouge worker enters the factory and runs the production machine off the books"
If you can run the hardware manufacturing off the books, I don't see how access to the driver source code would help. You would just ship the official binaries.
Which continues to moot the relevant point: Nvidia are withholding necessary software specs which not only aren't useful in reengineering their hardware, but which fail to protect against fully independent attacks (ghost shift manufacture) which at least allow duplication of current physical product if not producing a superior hardware product.
"Very low serial numbers, like very low MAC ID addresses, are a hallmark of the “ghost shift”, i.e. the shift that happens very late at night when a rouge worker enters the factory and runs the production machine off the books"
http://www.bunniestudios.com/blog/?p=918