He seems to have been the 'super-spreader' who treated something like 300 cases (see my tagline for details) in Guangdong province THEN travelled to China ...
Can you imagine being subjected to 300 slightly different mutations THEN leaving the country to infect another? I think that's what did it.
It is just my unsubstantiated ill informed opinion that the majority of the SARS cases are either a milder form or viral pnuemonia. There is no test that can be relied upon to diagnose SARS according to the WHO's guidlines. It is diagnosed symptomatically.
The strain this guy had was a nightmare. Everybody this guy touched died as far as I know. They also became "super spreaders".
It is all a moot point now. The mini epidemics he spawned are stopped except in China.
P.s. I am not going to China anytime soon and the forced quarantine of the guy in New York makes me think our government is serious.