A person on disability, supposedly can only make $1000/month without having to report that income to the IRS. If a person on the show is shown to make more than they should, revealed in a case before Judge Judy, does she report this to the IRS?
Neither "Judge Judy", nor anyone connected with the show, is to the best of my understanding required to make such a report to the IRS, or to any other government agency. But neither are they forbidden from making a report should one of them choose to do so. For the matter of that, you, or anyone who saw the show, could make a report.
I did not see this particular show, and I don't know how clear it was that the person was in violation. It might be that some exception applies.
Also, news reports say that the IRS is currently underfunded and overworked. A disabled person making a bit over $1000 per month probably does not owe a large tax bill, even if in violation. Such a case might well not be a priority for the IRS.
Oh by the way, failure to report income is not "tax fraud", that is making false or misleading reports, and I think there is also an intent requirement. "Failure to file" is illegal, but under a different provision.