Furthermore, the report submitted by the Civil Service Bureau revealed that, when consulted on Mr Leung's application, none of the four permanent secretaries mentioned the Hung Hom development as a relevant factor. The public viewed this glaring omission with disbelief. As if adding insult to injury, Mr Leung expressed surprise that this factor had not been taken into account by the government.

The public also noted a 'disturbing' fact in the bureau's report: of the four permanent secretaries involved in commenting on the application by Mr Leung, only one raised concerns about possible public perceptions. The other three - all administrative officers - considered the application in order.

There is no denying that disclosure of how Mr Leung's application was processed has tarnished the reputation of the civil service chief and the senior ranks, particularly the elite administrative officers. One of the key considerations in processing such applications is 'whether the officer was involved in any contractual or legal dealings to which the prospective employer was a party'.

This being the case, the government should conduct a management review to discover what actually went wrong with the internal consultation process in Mr Leung's case. It is incumbent on the administration to take measures to restore the public's confidence in the integrity and professionalism of the senior civil service ranks.

In offering her apology, Miss Yue said she intended to stay on. Mr Tsang also said she did not need to resign. This is right. She has been humbled publicly. Public interest will be better served if she can help prevent similar things happening again.

Before the release of the bureau's report, the Advisory Committee on Post-service Employment of Civil Servants was criticised over its gate-keeping role. It now transpires that the bureau's submission to the committee did not mention the critical issue of the Hung Hom development. Also, before considering the application, the chairman made a declaration of interest that Mr Leung was a former schoolmate. So, the report at least vindicates the reputation of the committee and its chairman.

Indeed, in considering any improvements to the present arrangements, the new committee proposed by Mr Tsang should recognise the importance of preserving an independent advisory committee to vet post-service employment applications. Nevertheless, there is a case to expand its membership to include one or two members, such as a former or serving legislator, so as to enhance its credibility to the general public. A retired senior civil servant, with no business ties, may also be worth appointing.

In proposing the review, Mr Tsang said that in regard to the post-service employment of ex-civil servants, it should be noted that more and more civil servants are moving over from the pension to the Mandatory Provident Fund retirement scheme. This is a valid point that should be addressed.

In a way, the present arrangements have already anticipated this transition by applying similar post-service employment restrictions on non-pensionable officers. For example, a senior non-pensionable directorate officer (on the same pay scale as a permanent secretary), with six years or more of continuous government service, is subject to a three-year control period when he or she leaves government for any reason. The government may also impose a minimum sanitisation period on these officers on a case-by-case basis. So, it should not be too controversial to make suitable adjustments for those on the MPF.

It is appropriate to review existing systems from time to time and make improvements in the light of the latest developments. The present arrangements governing the post-service employment of ex-civil servants were last reviewed in 2005. It may be time for another review.

I hope the starting point is to examine what actually happened in Mr Leung's case and draw lessons from it. I also hope that civil service groups, as well as the public, will have an opportunity to express their views to the committee. The right to employment of former civil servants has to be balanced with the concern of the public over any real or perceived conflict of interest, or suspicion of rewards for past favours. I am afraid the review may be arduous for the committee and the secretary for the civil service, particularly in the present political climate.

But no improvement can make a perfect system. Ultimately, it is the men and women behind the wheels that make the system succeed or fail. The wheels of bureaucracy also need to be examined critically in the review. After all, they spun in the wrong direction in Mr Leung's case.

Joseph Wong Wing-ping, formerly secretary for the civil service, is currently an adjunct professor at Chinese University of Hong Kong