It shows Tang has failed to learn a lesson about the troubles that may come from officials' desire to "pre-empt embarrassment" for their boss. Remember the heavy-handed behaviour by police officers during then vice-premier Li Keqiang's visit to the University of Hong Kong in August 2011?

Tang's interference in the running of the two programmes also stemmed from his intention to pre-empt embarrassment to the government.

As a civil servant, Tang needs to remain neutral and let the station get on with its work, unless he wants to follow in the footsteps of former security secretary Ambrose Lee Siu-kwong and former education chief Fanny Law Fan Chiu-fun, to become a delegate to the National People's Congress. If Tang's heart is truly with RTHK, he doesn't have to interfere with the station's editorial direction or befriend Beijing.

The public is calling for Tang's resignation, because Hong Kong people will not tolerate political interference in editorial independence, as it concerns the freedom of the press and freedom of expression.

To be honest, RTHK has landed in this mess because of a reluctance to become an independent public-service broadcaster with a board of governors elected by community groups, detached from the government system.

In the long term, the best way to guarantee the station's editorial independence is for it to be operationally independent, which means all aspects of its operation, such as personnel and finances. As long as it continues to be funded by the government, it will not bite the hand that feeds it. Hence the government will always find a way, either directly or indirectly, to control and interfere.

Over the years, and even before the handover, the government on many occasions tried to pave the way for RTHK to become an independent public-service broadcaster. Many rounds of consultation were conducted and many attempts were made to help the station become independent from the government structure.

All these efforts proved futile because of strong resistance from staff due to personal interests. After all, remaining in the public system means financial security, and thus a strong guarantee in terms of remuneration and other perks. Most employees would choose financial stability over the station's independence.

Chief Executive Leung Chun-ying, who suffers from low popularity ratings, will do all he can to regain Beijing's trust. Controlling the media, such as RTHK, is likely to have been a "political mission" assigned to him by the central government. So there is no way he will let the station become independent. The reality is that RTHK has missed the boat.

RTHK staff came out to criticise Tang not because they are true defenders of freedom of expression, but because they fear that, one day, they will become a political victim, like Sze, if they refuse to obey orders from management. Their action was mostly motivated by personal interests and self-preservation.

One good example to illustrate this point is the fact that RTHK remained silent when DBC Radio came under political pressure from the government because of its anti-establishment stance.

After Tang took the helm at RTHK, two of its prominent talk-show hosts did not have their contracts renewed. At that time, few from the station criticised this seemingly political manoeuvre. Perhaps it was because the two hosts were not civil servants and their cases were not worth fighting in the eyes of the RTHK staff who are civil servants. How shortsighted of them.

In the past, staff have helped to preserve the status quo.

It's inevitable that the government will continue to stifle freedom of expression. Interfering with the editorial independence of RTHK is one way of doing so.

People must come out to vehemently fight against this, while also reinforcing this freedom by supporting the rise of new media outlets in order to expand the media landscape and increase their chances of survival.