A US amphibious warship USS Arlington[0] was sailing near the nordstream location. It left a Swedish island in the middle of the Baltic Sea 6 September 2022.
Meanwhile, the US controversially transferred SEALS to Germany earlier in October 2022[1].
USNS William McLean left a German port 5 September 2022[3] (there are also port call records) and headed to meet the USS Arlington on 10 Sept 2022[2] to transfer cargo.
USS Arlington loitered around docking in Lithuania and only reaching the straight near Denmark on 22 Sept.[2]
USS Arlington then meets the exact same USNS William McLean for another cargo transfer 20 days later and just 6 days after leaving port.
Where USNS William McLean went after I don't know. I know it docked somewhere close as there's an entry for 26 Sept 2022, but I don't feel like paying to know the exact location.
If you were conducting a SEAL operation on the high seas, a San Antonio-class ship would be a perfect launch vessel. A cargo exchange would be the perfect cover to swap ships. Delayed bomb detonation isn't dangerous and could explain why only 3 of 4 pipelines were impacted (aka, something went wrong with one).
I'm not saying it 100% happened (and is somewhat at odds with the anonymous source in this story), but to me, it seems like the US had the motive, means, and opportunity.
[0] https://www.navy.mil/Press-Office/News-Stories/Article/31497...
[1] https://www.stripes.com/theaters/europe/2022-10-20/seals-gre...
[2] http://www.uscarriers.net/lpd24history.htm
[3] https://www.youtube.com/watch?v=h3pp-ehkS2o