I just wish the article had been clear about that. Instead it just rambled for several paragraph, and replaced the threat with a vague statement about how you'd "hold them accountable", which could mean a dozen things.
Also, I concur with the GP except that I agree this is a use of game theory, but only in the trivial sense that any offer of reward to those you like (as used by other PACs) is game theory.
"If one of you informs on the other, he'll get off with a 1 year sentence, and the other goes to prison for 10 years. If neither informs, you both go to prison for 5 years."
Does that sound like game theory, or just carrot-and-stick?
Here are other examples of game theory in real-life. I'd say we're in the same category:
"We would like you both to take a disclosure pledge. If one candidate takes it, and the other doesn't, we may go after the one who doesn't."
Then we see what happens.