What exactly does 'academic freedom' mean to Johannes Chan and his supporters?

It is widely thought that the decision by the University of Hong Kong council to reject Johannes Chan Man-mun's appointment as a pro-vice-chancellor is connected with the fact that he is "an internationally renowned legal scholar and administrator who champions the fundamental values of human rights and the rule of law". The failure to provide credible reasons for not appointing him is, therefore, a "litmus test for academic freedom", according to a Post article by Jerome A. Cohen and Alvin Cheung.

These sentiments are echoed by Chan himself who says that a publicly funded institution, acting in a matter of general interest, should be transparent in its reasons for decisions. There is even talk of a judicial review to see whether the institution took into account irrelevant considerations in reaching its decision.

Any influence of the Hong Kong government, which has six nominees on the council, will be widely assumed to be nothing more than a "diktat" from Beijing. So, it is easy to widen the Chan nomination dispute to include evidence of a failure of China's "trumpeted support for the rule of law", particularly in view of the "personal smear attacks" on Chan by the pro-Beijing press in Hong Kong (Cohen and Cheung again). Chan has counted 350 such attacks.

So it may appear that Beijing is directly engaged in an attack on the academic autonomy of HKU, one more incident in a global struggle where the Chinese government is itself seen as incompatible with "the fundamental values of human rights and the rule of law". No wonder Chan is seen as a threat! To my knowledge, the content of these smears has not been addressed in English-language media in Hong Kong. They are in Chinese, and I asked one of my mainland PhD students to translate one extensive article published when the smear campaign was at its height. The article included such criticism as: Chan's policy of having assistant professors without research degrees supervising mainly mainland PhD students; the faculty holding apparently academic meetings which are actually an expression of political activism; and appointing many senior Western academics who are not noticeably academically productive in research while in Hong Kong.