In my opinion, it is both "interesting" and "fishy" to see someone do this to his former employer. On one hand, he may be revealing some real problems inside (parts of) the company which other people (either inside or outside AMD) wouldn't know or recognize. On the other hand, he may be right about things that he claims to know, but due to his bitterness wrong about the conclusions.
I believe in this case, it is the latter. In any rate, lets go through some of his points below and see, assuming these are all facts, how true or false they can be:
AMD has not been financially successful since "K8". This may not be due to any of AMD's problem, but Intel's monopoly tactics. One should ask why was AMD "financially successful" during the K8 days in the first place? Was it because only those who designed K8 knew that they were doing? Was it because they hand crafted every transistor? Or was it really because both Itanium and Netburst terribly sucked in real-world tests? I'd argue it's only the last.
AMD has been losing key employees. Losing employees is tough for any company. Yet, sometimes a company has to lose weight when it is evolving and before it can start growing again. The question is not whether someone did something grand. But whether he will do something grander. What would have been the grander next step after K8? Could AMD have beaten Intel by making an over-complicated "K9" with SMT and turbo mode and everything else? I'd argue with the required design and verification efforts, no "key employee" could have made this happen timely and cost effectively.
AMD is not hand-instantiating designs
AMD did not make any new architecture after K8. Architecture is a flimsy thing. At their hearts K8 is no more than K7 plus extra 64-bit registers and integrated NB. The way instructions are broken down to macro-ops and micro-ops, the basic organization of the ROB and the separate INT and FP schedulers are all the same between K7 and K8. HyperTransport based NB, the exclusive L1/L2 cache and improve TLB gave K8 solid performance. But so are the improvements made to K10 like the shared L3, unganged memory, probe filter and greater scalability. K8's NB was designed to have up to 8P in a single system; few wanted that over the years. Today K10-based Magny Cours processors allow 48 cores with perhaps tighter inter-core communication. I bet Intel very much want to do the same.
In conclusion.... is that guy simply stating the facts, or is he bad-mouthing his former employer? Personally, I think what he did was immature and immoral, even if what he said were facts. I was told that there's been some political struggles inside AMD during the post-K8 years, and I also believe that such politics must've brought with it some waste of time and money as well as loss of talents. But still.... in my humble opinion, that's no good excuse for picking on your former exployee and starting a public brawl fight.