A regulator should not pick and choose who to punish, in secret, and for unwritten rules. That's ridiculous, and this kind of secrecy and ambiguity is not an example of good governance, fair treatment, or competitive markets.
In a competitive market where government treat everyone equally (no picking winners and losers) everyone abides by the same rules, transparently. That's not what happened.
In fact, when government decides to meddle in markets in secret and without any written rule or law, this raises fear of exactly that. Probably in this case, the end result seems to be not unjust, but the method is horrible, and I have no idea why they did it this way.
And yes, this kind of market meddling, or "picking winners or losere," is a type of market meddling, not unlike what I linked to.
I would suggest going back over the article to see where your confusion started, and also the posts here, and my other response to you.
I do agree that those rules should be transparent and not "unwritten" though.