I get that, and it is odd. Though Russia can also wash its hands off of that ship. IIRC it is Maltese-flagged, owned by a Maltese company, and the crew is international. It "just so happens" that it contracts for Russian cargos. Russia may perhaps (?) be the ultimate beneficiary but it's also not strictly speaking Russian.
Back to my question: can all these justifiably concerned countries not simply refuse access for this ship, end of story?
> can all these justifiably concerned countries not simply refuse access for this ship, end of story
Pretty much. Entire crews can be (and are) abandoned in international waters for years at a time if the company decides they don't want to deal with the ship any more.
Which makes some sense as to why the crew would bring the ship down to the North Sea from the far northern Norwegian coast (weather this week: down to 2 degrees C, wind up to 40mph). If you think you might be abandoned in late September, and ports in Murmansk and Arkangelsk could also decide not to admit you, do you want to overwinter at sea in the Arctic, or go literally anywhere else? And that's if the company does forsake them, which is also a hypothetical. More likely, the company also would probably rather the ship is not at risk of being disabled in the Arctic considering they presumably couldn't get a guarantee readmittance to the port of origin and decided to at least get to relative safety down south with better weather and near countries that at least plausibly would lift a finger if the ship really was at risk.
Back to my question: can all these justifiably concerned countries not simply refuse access for this ship, end of story?