That "evidence" is at best circumstantial. One counterfact is that Nordstream pipeline at the time of it's destruction was not transporting gas, i.e. it had already been shut down and abandoned by the Germans.
It's certainly better evidence than was ever offered for the supposed Russian role in the incident. If all your news is from English-language war media, you won't be convinced by Sachs. (Who is refreshingly frank with respect to a variety of issues now that he's been through that whole Lancet task force farce.) Outside Europe and North America, however, no one believes it was the Russians.
The pipeline was no longer transporting gas, but it certainly hadn't been "abandoned". That would have been monumentally stupid, especially in the context described by TFA.