Good piece, and I think he points out some clear problems with the exact events that Hersh describes. I think the lack of a verifiable path for either the ship carrying divers or for the plane that supposedly dropped off the sonobuoy do make it less likely that Hersh's version actually happened. The author's conclusion is that this is because Hersh's source was making things up, but I think it's also compatible with someone who heard about the plan but didn't fully understand it. Or possibly, heard about it before it was finalized. Hopefully more details will come out.
His closing question is "Why leave one of the two Nord Stream 2 pipelines intact"? I haven't seen it discussed much, but apparently there actually were 4 leaks, with one pipeline being damaged twice. One possible explanation would be that this was a mistake in the execution by whoever did this, with one pipeline somehow getting two explosives planted. Here's a Sept 22 article about the discover of the 4th leak: https://www.reuters.com/business/energy/fourth-leak-found-no...
Why does the bombs have to go off immediately when the plane drops the signalling device? If you got through setting all this up, I am sure you can also figure out how to delay the explosion so there would be no obvious connection to a plane flying over.
Sure: when a large amount of gas is released to bubble up, the average density of the gas/water mix can be too low for the maximum displacement of a ship passing above to carry it's weight. Ship drops beneath the surface until it hits pure water or a mix close enough, and most ships aren't built to recover from that.
His closing question is "Why leave one of the two Nord Stream 2 pipelines intact"? I haven't seen it discussed much, but apparently there actually were 4 leaks, with one pipeline being damaged twice. One possible explanation would be that this was a mistake in the execution by whoever did this, with one pipeline somehow getting two explosives planted. Here's a Sept 22 article about the discover of the 4th leak: https://www.reuters.com/business/energy/fourth-leak-found-no...