The only anchor in reality appears to be Biden suggesting that they knew how to take it out which seems like a pretty weak place to build a large story.
What I find particularly odd is that this entire thing appears to be based on a single, unnamed source "with direct knowledge of the operational planning".
Why is that weird? Assuming this is true, there would be rather many people with such knowledge. One of them may feel the need to talk. Would you expect such a source to be named?
Also, I find it a lot easier to imagine why the US would want to do this, than why Russia or Germany would want to do this.
Or, since the pipelines are well known and not difficult to reach, basically everyone with access to explosives, a boat a divers with explosives skills. None of which is particularly hard to come by.
Thus you cannot easily imagine any of the Baltic states, Finland or Sweden doing the deed.
Norway is conceivable-- but they're not really all that active in the Baltic sea, Ukraine is conceivable-- but it isn't actually super easy to do what was done. Blowing up the pipeline would have been easy, but there were several bombs, and they were, as I understand it, quite big, and this would be removal of resources from things closer to the fighting.
Norway is difficult for political reasons though-- would they really screw over their neighbouring countries in the EU?
Thus all these countries are all unlikely choices.