People get confused about miners based in China and Chinese Government mining.
Chinese Government, as far as I know, there are no miners from the chinese government. China cannot control bitcoin.
Additionally, even if Chinese government did, they wouldnt be able to revert a transaction. Only one, and then they would all be blacklisted from all bitcoin nodes and kicked out of the network.
The chinese government has full control over chinese businesses. There is no difference between the Chinese government and companies like Alibaba. Even Joint Ventures have to give all control over to a Chinese partner.