Not really.
AMD has its own version of 'bumpgate'... of course this wasn't blown up on the internet (you could ask yourself why... but that'd get us back on topic with immoral business practices and all that, and we wouldn't want that), but that doesn't mean it doesn't exist.
See exhibit A:
http://www.humus.name/index.php?page=Comments&ID=283&start=8
AMD's GPUs also use a different design, have different power/temperature specs etc... so using the same solder may not result in the same problems. There are too many unknowns to draw any conclusions.
Aside from that... yes, AMD and nVidia will probably have had some input on what to use exactly... but especially nVidia has no first-hand experience with making chips at all, so they will just have to go by what the fab advises (and TSMC has made quite a mess of their 40 nm process as well... both AMD and nVidia complained that the final product was nowhere near what they originally specced it out to be. It happens).
AMD may have had some extra inside-info from their own fabs, who knows?
And well, there's still people making decisions. It's all about evaluating risks (we've been over this before).
By the looks of it, either nVidia didn't estimate the risk as highly as AMD did, or nVidia was willing to take more of a risk than AMD was.
We don't know for sure. All we know is that nVidia took the gamble and lost. It happens.