One rule for the authorities and another rule for everyone else?

In general, Singaporeans are fine with rules. The problem only arises when it appears to be one rule for some while another for others. For rules to be respected, it has to be applied consistently and across the board.
Back in 2017, the Public Service Division (PSD) said in a statement to The Straits Times (ST) that civil servants needed to declare additional trade or work that drew income to ensure that there were no conflict of interests.  That statement to the ST followed the fining of a staff sergeant of $2,000 in default of a 2 weeks detention by General Court Martial, for giving 140 rides using the GrabHitch app between October 16 and March 17 2017.
As a general principle, I have no issue with this.
Civil servants are after all paid for out of the public purse and there should therefore be a certain degree of accountability.
Fast forward two years however, it is apparent that this rule seems to have been forgotten when it was announced by the Monetary Authority of Singapore (MAS) that it is fine with its Chief Fintech Officer, Mr Sopnendu Mohanty, to also be an adviser to the state government of Odisha concurrently.
The reasoning given my the MAS seems to suggest that because Mr Mohanty is not getting compensated for his role in the Odisha state government which is apparently in his “personal capacity”, there is no conflict of interest. This begs the question, is monetary compensation the sole arbiter of determining whether or not there is a “conflict of interest”?
Surely, Mr Mohanty being in a high position in the MAS will give him access to confidential information. What are the checks and balances to stop him from sharing such information with the state government of Odisha? Do benefits always have to be in monetary in nature? What about contacts, business relationships and connections which can often times be worth much more than immediate monetary compensation?
If I use MAS’s reasoning, shouldn’t dual nationality also be allowed in Singapore? It is not as if, a Singaporean will be gaining monetary compensation for having dual nationality if he or she already lives overseas?
If Mr Mohanty’s dual role in the MAS and the state of Odisha is permitted, why then was a mere staff sergeant fined just for giving Grab rides? It would appear that the stakes of permitting Mr Mohanty’s dual role is far higher than that of a staff sergeant trying to earn some spare cash?
Who decides whether or not something is a conflict of interests? It cannot be applied so unevenly and unfairly.