This can be interpreted in different ways, therefore I am of the opinion that it is not enough for red. Signature is payment for some kind of service, or promotion, and if you remove the ad from your sig space, you will not be paid.
In Ratimov's case, he wanted to pay for the improvement of his reputation, but he didn't get it, maybe that's why he doesn't want to pay.
But the offer was not contingent on him getting a certain amount of reputation or something like that. The way the offer was made it looked like him calling himself a "sponsor" was all he wanted out of it. He gets that for about 11 months out of 12, and then withdraws the offer. Does not seem right no matter how I try to look at it.
And even IRL courts often don't consider "fairness" in contract disputes. In other words, if Sym engaged in a bad deal, that's kinda his own fault.
Anyway, I'm not advocating for red trust, but I also probably wouldn't oppose a flag if any of the participants of the contest can provide solid reasoning based on the facts of this "sponsor" deal alone (without detours to plagiarism and all the other drama).