You know what this all makes me think of? Imagine a little boy is poking his sister with his finger, and she complains, and his mother says "Timmy, stop touching your sister!"
If Timmy picked up a stick and started poking his sister with that, instead, and defended himself by saying "You said I had to stop touching her, but you didn't say I couldn't poke her with a stick", how do you think his mother would/should react to that sort of pedantic rules lawyering? Do you think the mother would respond that Timmy raised some very valid points, and that it was her fault for failing to anticipate that he might poke his sister with a stick, and that he could get away with doing it just this one time but going forward could he please kindly refrain from poking his sister with a stick, as well? Should she be forced to enumerate all of the other objects that Timmy is not allowed to poke his sister with, as well as listing any other potential actions which Timmy should refrain from taking, all while hoping that she manages to think of everything without leaving anything out? Or is it more likely that Timmy is about to find himself disciplined back to the stone age to send a clear and unmistakeable message that conniving and rules-lawyering will not be tolerated, to say nothing of tacitly encouraged? Because that's kind of how I think a good commissioner should react here. It sucks that commissioners have to be mommies to a bunch of grown men, but that's sort of the job description.
If the commissioner says "well, there's no rule on the books" and lets them get away with it this season, he's just begging them to try to find other ways to game the system going forward.