Possible, though that would require sending Ukrainian ships and agents a very very far way away. I don't think a clandestine Ukrainian operation on the other side of Europe is very likely in the middle of a war on their own territory.
>The Germans were warned in summer by the CIA about a possible attack scenario on the Nord Stream pipelines. U.S. intelligence claimed to have intercepted Russian communications in which concerns were expressed about possible Ukrainian attacks on Western infrastructure. The Ukrainians allegedly tried to rent a boat in Sweden for this purpose. The CIA did not consider the scenario of a Ukrainian attack to be very credible, but the mere fact that the possibility of an attack on Western infrastructure was mentioned by the Russian side prompted the Americans to warn the Germans about the scenario.
He said that she said that he heard that she said that he was planning to do it.
Obviously it was him!
It's silly to give any credibility to this type of rumour. We should all wait for hard evidence and if there are none or if it can't be made public, then for courts verdicts.