Well, typically, the Stalinist show trials are called such because a trotskyist group held trials for the individuals in absecentia afterwards that supposedly absolved them of their crimes, by throwing out all of their confessional testimony as being made under duress (which tbf it probably was). Literally holding show trials.

That said, what the trotskyist group failed to do, of course, is place it in context to the kinds of trials that were taking place in the U.S. where they were based out of, was understand that what the USSR did was exactly the same level of evidence and scrutiny that was done in basically every other country for treason. The more I read about these old Trotskyist groups, the more I realize that they held the USSR to an impossible standard, while actively undermining it's foreign policy in the countries they lived in, while not holding those countries to the same standards as the USSR in terms of them offering direct assistance. Basically, they were willing to do critical support for capitalist countries, but not for countries that called themselves communist. The worst kind of schemers and backbiters.