Proof of Poincaré Conjecture: Perelman vs. Yau

In a recent article by New Yorker, Russian mathematician Perelman explains his decision of refusing to take the Fields Medal, and on Shing-Tung Yau's (丘成桐) claim for contributions his people have made for the proof of the Poincaré Conjecture:

“As long as I was not conspicuous, I had a choice, either to make some ugly thing or, if I didn’t do this kind of thing, to be treated as a pet. Now, when I become a very conspicuous person, I cannot stay a pet and say nothing. That is why I had to quit.”

I think Perelman is a true scientist with class. I do have one question though, could the reason for his refusal to accept the Fields Medal be that he himself is not convinced that his proof is flawless and final?

I am not sure if I have the same respect for Yau. To make no mistake, Yau was, and probably still is, a great mathematician. What I don't like is that, when someone like him gets famous, he becomes a politician and asserts influence that can be viewed as a violation of academic ethics.

Yau has tried to argue that the US media misquoted him - to no avail, judged by comments on the Internet. That's one thing he should be more smart about (and that I learnt a lesson first-hand myself several years ago): be careful with what you say to the media --- he announced his proof in a news conference in Beijing. Any words he spoke to the media are no longer his possessions - how they are used or interpreted is beyond his own control. They can help you, as they did in China, or it can haunt you as they did in US. The worst: Yau's reputation as a great mathematician is at risk.