While a false flag operation cannot be ruled out, I don't think the case is as clear-cut as you suggest.
> Nobody had incentive to blow up empty pipes except Russia.
I disagree: Russian gas was the one leverage Russia had over Germany. Blowing the pipeline ensured that Germany wouldn't be able to get out of the conflict quietly - "Germany still receiving Russian gas" would not receive as much condemnation as "Germany repairs Russian gas pipeline".
> Ukraine doesn't hide successful attacks on Russian infrastructure, because Ukraine has legal right to defend itself.
True, but Ukraine doesn't have a legal right to sabotage the infrastructure of its allies. I live in Germany and I can tell you: that first winter was pretty bad for everyone, with plenty headlines about people who could no longer afford their heating costs. If it had been known that it was Ukraine's doing, popular support for the war would have sunk a lot.
how so, if Germany did shutdown almost all their nuclear power plants? Experts say that would be impossible to "simply turn it on back", because of lack of professionals capable to work on that and that each minute that we wait, harder will be to bring them back...
> Nobody had incentive to blow up empty pipes except Russia.
I disagree: Russian gas was the one leverage Russia had over Germany. Blowing the pipeline ensured that Germany wouldn't be able to get out of the conflict quietly - "Germany still receiving Russian gas" would not receive as much condemnation as "Germany repairs Russian gas pipeline".
> Ukraine doesn't hide successful attacks on Russian infrastructure, because Ukraine has legal right to defend itself.
True, but Ukraine doesn't have a legal right to sabotage the infrastructure of its allies. I live in Germany and I can tell you: that first winter was pretty bad for everyone, with plenty headlines about people who could no longer afford their heating costs. If it had been known that it was Ukraine's doing, popular support for the war would have sunk a lot.