That is a hard question to answer. Each manufacture keeps their product designs so secret that it difficult to determine (Unless Leaked) what was or is the problem with the Video Chip.
You might remember the scandal with the first Intel Pentiums Processors which would not calculate correctly (Bad Math Co-Processor). Even with the all denials, feature cut-offs, supposed software fixes, etc. to try to over come the problem; the issued ended with a Complete Redesign of the Processor Chip plus a class action product replacement law suit.
A similar issue occurred about (5) years ago when Builders, such as myself, began experiencing early motherboard failures across many brands. It turned out (one) supplier of Talenum Capacitors cheated with the wrong chemical mixture during production (an employee problem). Fortunately, Asus never used the OEM supplier so their MBs were not affected and my machines were not either.
All of this being said, I guess the real answer to your question is that the public (consumer) may never know what the exact problem is / was with the NVIDIA Video Chip. The details will fade into oblivion as other more pressing issues take center stage.