Technically, the prof is correct.
Stalin was never brought up on any charges by any court, except that of popular opinion.
To a leftist, it’s only the technicality that counts here. The fact that he ordered the murders of tens of millions of people is irrelevant to good little commies like the prof.
Yes and Hitler never killed any Jews.
I imagine most commies would say that it is a lie that millions died. They wouldn’t bother with technicalities. The big lie repeated over and over is what tyrants and their defenders do.