Part of the reason the medical is so tough in China is due to the punitive Chinese culture. If a foreign captain becomes incapacitated and the inexperienced FO (not all are inexperienced) has issues with getting the aircraft on the ground and there is an accident or incident, the Chinese authorities will look for someone to be blamed and punish. There is a good chance they will look to the doctor who certified the foreign captain who was incapacitated. In the Chinese mindset, if the doctor had done his job correctly the captain would have never have had any issues. So the doctor must be punished for his failings. A good example of this is about two years ago a foreign captain had a mild stroke while in flight. Now the Chinese medical has added a neck ultrasound (to look for buildup in the arteries leading to the brain) and a CAT scan of the brain.