Police in Taiwan sized the dud chips in January following a tip-off from AMD's Taiwan operation. The CPUs, a mix of 32-bit and 64-bit parts, were said to be defective and earmarked for destruction. According to police reports, the chips came out of AMD's Singapore testing plant and should have been destroyed two years ago.

At the time of the seizure, more than 1m such parts, then valued at TW$300m ($9.4m) had already been shipped to China and Germany, Liberty Times says
The paper said that AMD has begun legal action against Chen.
So 1,000,000 bad chips on the market * word of mouth = a lot of people thinking negatively about AMD

I'm sure news of how it happened won't spread as fast as the news of a 1,000,000 bad CPUs.