I can't see how Match.com could possibly defend their case in court if they tried to sue. They'd essentially be asking a competing firm to reveal their trade secrets.
Even if they sue, it's Canada. You can only get actual damages (which you also have to prove), lawsuits in Canada aren't lotteries (like in the US).
Again, it really doesn't look like they are doing that at all. They are just asking them to prove their marketing claims. My guess (IANANANAL) is that Match could sue for false advertising charges? Or bring evidence to the FTC? Dunno. But they aren't asking for their trade secrets.
False advertising is illegal.
True, but the burdon of proof is on the prosecution. If they have proof, the they could sue, but this looks more like a flimsy attempt to gain information.
I believe there's some sort of legal precedent about coming to court with clean hands when you're bring up charges against another party. And Match would be flirting the line of hypocrisy if they want to talk about false advertising.