Since Xiao is directly or indirectly affiliated with NIH (or whatever US research agency, I haven't followed all the detail), this would be a serious issue and not just an academic one. It would be related to foreign policy and what those 31 referred to as human rights. All research using US money (including private) must adhere to certain ethical rules and U.S. laws probably applies, to him, his collaborators and their grants.

If there is indeed a problem, the issues are no longer academic :) You know what I mean.