You can call it mental gymnastics, but I just call it thinking. I notice you're not really engaging with the point, which is that yes, Russia attacked its own infrastructure, and that hurts their own interests, but the effects of the attack – 1) creating more uncertainty on the European energy market on the day a Norwegian pipeline opened; 2) creating a sense of insecurity in the states around the Baltic sea; and 3) creating distrust between NATO members – are all worth the price to the Russians, because they are losing their war. One moment we're discussing nuclear warfare and mutually assured destruction, and the next we're not considering Russia blowing up some of their own infrastructure. Compared to M.A.D., blowing up a pipeline seems like a pretty cheap deal if it would benefit the Russian war effort.

So, let's do some more thinking. What would USA have to benefit from attacking the pipeline between Russia and Germany? A higher price for their LNG, so more money from Europe (economically weakening their ally), and if it would come out that USA did it, it would lead to severe fractures in NATO — not at all to the USA's benefit. And how, if the USA did it, would it have increased Russia's inability to sell gas to Europe? The flow was already zero, with no prospect of it returning anytime soon, sabotage or not. According to you, the USA sabotaged an ally, at the risk of ending NATO, at almost no detriment to Russia, for some increased LNG sales money. That, I would call mental gymnastics.

Mental gymnastics? It’s what Russia is best known for. Applying Occam’s razor brings you precisely to the conclusion that it was Russia.