The key message of SFC’s statement is here:
In considering the implications of the sanctions, intermediaries are expected to carefully assess any legal, business and commercial risks that they may be exposed to. We would expect any response to the sanctions to be necessary, fair, and have regard to the best interests of their clients and the integrity of the market.
SFC’s standpoint is obscure, but I pay attention to the words “necessary” and “fair”. It appears that SFC does not urge intermediaries to enforce the US sanctions if doing so is unnecessary or unfair.
On the other hand, HKMA’s standpoint is clearer. In its circular to authorized institutions, HKMA states that:
Hong Kong fully implements targeted financial sanctions in compliance with United Nations Security Council Resolutions…
…unilateral sanctions imposed by foreign governments are not part of the international targeted financial sanctions regime and have no legal status in Hong Kong.
In assessing whether to continue to provide banking services to an individual or entity designated under a unilateral sanction which does not create an obligation under Hong Kong law, boards and senior management of AIs should have particular regard to the treat customers fairly principles.
HKMA seems to imply that enforcing the US sanctions by banks is not a fair treatment of those 11 individuals on the SDN List. Interestingly, in the past HKMA would not give such advice when the sanctioned individuals/entities are non-Chinese (say, from Iran).
Banks are not obliged by Hong Kong law to follow the US sanctions. But who can excuse them from being sanctioned by the US government if they continue to maintain business relationship with those 11 individuals? On the contrary, if banks enforce the US sanctions, would they (and their management) be charged under the Hong Kong national security law? It sounds like a Catch-22 situation.
I always think SFC is more "politically neutral" than HKMA. This is another evidence.