I've observed the baffling tuning issues Susan points out in her post, most recently after tuning for Lang Lang here Urbana a few years ago. I heard unisons wandering a bit during the performance, but upon inspection shortly afterwards could find nothing out of sorts.
I've also come across those pianists who manage to trash unisons, regardless of how solid the tuning, and others who perform with equal intensity but walk away with clean unisons. I perceive it as an excess testosterone, if you will, driving the piano beyond it's capacity. I'd love to have heard the Russian pianist explain his technique! Self-healing tuning indeed. I wonder if others have observed this and can offer a plausible explanation?Finally, you make a very good point about the Russian school of piano performance overcoming the impossible adversity brought on by the wretched governments!