Very important to understand that making $500k speculatively is not evidence of an 'edge', nor is trading frequency evidence of the absence of luck. From March 2009 through much of 2010, the market was strongly bullish - if his algorithm showed a positive market bias then his returns would primarily be a function of timing (read luck: and there are a million variants on the nature of the bias that could be unwittingly responsible for his returns, despite the frequency of trades).

We cannot even tell if $500k is a good risk adjusted return - we have no information on volatility, nature of the exposure or most importantly how much money he started with?

Not exactly shocked Jim Simons didn't return his email. But completely shocking that he walked away from a successful automated trading strategy... the only thing rarer than a free lunch is a man willing to walk away from one. suspect.