Hong Kong is well aware of potential in flight transmission. Last year flight CA-112 (Air China) from Hong Kong to Beijing resulted in at least 25 on board transmissions on March 15. The virus transmitted from Hong Kong (Prince of Wales hospital) to Beijing, infected many Health Care Workers in Beijing and the two stewardess on board were the index cases for Hohhot near Inner Mongolia.
In addition to the above mainland outbreaks, 9 members of a Hong Kong tour group, 6 members of a Taiwanese business group, and two government officials from China developed SARS. One of the officials then infected Pekko Aro, an official from Finland. The airborne transmissions brought SARS inside the gates of the ruling party.
I suspect that one SARS positive will generate an over abundance of activity.