I think TCH made a very a good point when he tried to explain the concept of conflict of interests - that many in the Parliament are lawyers and he is not. So why NOT get the CJ or a retired High Court Judge to explain ?
In essence, according to TCH (and later Mambo), two elements have to be present - duty and interest. If one of them is missing, there is no conflict of interests. The recusal removes the element of "duty", and therefore there is no conflict of interests, actual, potential and perceived.
The Ministerial Code is NOT a law, but if our Courts are required to explain the concept of conflict of interests, can we rely on TCH's layman explanation backed by Mambo who is the subject of the review ? If it's not a legal precedent, then what value does it hold ?
Potential Conflict of Interests
The need to recuse oneself from the decision-making implies that a potential conflict of interests is present (or has already arisen). Whether or not the recusal is able to negate the (potential) conflict of interests is another matter, but we can all agree that at that point of time there was already a potential conflict of interests without which a recusal would not have been necessary.
If one really wants to adhere to both the letter and the spirit of the Ministerial Code (and not just the spirit but not the letter), as soon as a potential conflict of interests arises, the prudent person will avoid the transaction altogether. The recusal cures any actual conflict of interests when the transaction is carried through, but it does not prevent the potential conflict of interests from arising. Ironically, it's because a potential conflict of interests arises that you need to recuse yourself.
When you visit Mandai Zoo, you are told NOT to climb over the fence where the tiger is crouching. If you climb over the fence, the tiger might or might NOT attack you. So if you climb over the fence, the potential of being attacked by the tiger arises immediately. What do you do ? You climb over the fence with a gun and two snipers behind your back ? Will that negate the potential of being attacked ? Of course not. It will only ensure that if you are attacked you will still be protected. The prudent way is to avoid climbing over the fence.
Perceived Conflict of Interests
This is even easier to understand. It has absolutely nothing to do with recusal or not. The need to have a Ministerial Review and devote 5 hours worth of Parliamentary session is SOLID EVIDENCE that there is a perceived conflict of interests. Otherwise, what is the Ministerial Review for if there is NO perceived conflict of interests ? Isn't the objective of the Ministerial Review to dispel negative public perception ?