At no point did I imply the Chinese were worse than anyone else at responding. I agree, the lockdown should be immediate, and exceptions should be publically do

At no point did I imply the Chinese were worse than anyone else at responding. I agree, the lockdown should be immediate, and exceptions should be publically documented -- 'incident 782: flight xyz with 10 pax was granted clearance to land as a medical transport flight, under authority of XYZ, regional medical coordinator'. I don't see requiring retroactive effect though -- just require those people to confine themselves and their co-habitants, and stand by to be contacted for contact tracing.