You might not take a close look, the one from Tsinghua is not second author, it is noted as an equal contributor. And there may be two western universities in total, taking into account of all authors. I like how your logics goes, that it is up to you to assign the credit as how much goes to who, everything doesn't fit your narrative doesn't count. As to your trivia, I don't think it matters, since his best research is done in MSRA, with coauthors that are mainland Chinese, not in that Hong Kong University.
Majority of authors of the papers are from China, the research is done by Chinese, mainly in mainland China, I believe they are Chinese enough, the point I want to make is obvious. Otherwise, I feel majority of the US CV papers would be disqualified because they are likely not done by locals here.
Last but not least, I was answering to the question as regards to good Chinese papers, not specifically from Chinese universities, not directly towards your question after all.