Well, what one could argue is that "Tetris isn't number one" was the untenable position, and "capitalism has sold more overall" was the irrefutable one.

Oh well, the 2 fallacies are very similar with a big overlap, but if I may summarize it down to the point that I find most important:

If someone is proven wrong and they don't take full responsibility for that (e.g. by trying to quickly push the discussion somewhere else where they're not wrong), talking to them won't lead you to the truth.