They and maybe the Germans would be the ones working on it. I suppose this could be some Russian 5D chess or something but I don't think Goat's potential scenario where Russia did this makes much sense.Origin = Russia. Do we trust them to do that?
Logically IMO, the Russians would want to have these pipelines online. It was their one big economic trump card they were going to be able to play this winter. With the pipelines destroyed or offline in a manner that is out of their hands, they lost their most effective weapon against countries like Germany to turn public opinion. The Germans couldn't get the gas turned on now even if they wanted to. God, nature, fate, a state actor, or whomever just took out Russia's most potent bullet over the next several months. The Russians should want those pipelines repaired as soon as possible because failure to do so over a longer term will have those European countries finding alternatives out of necessity. Once those alternatives are firmly in place, people become acclimated to the status quo.
This is a long winded way of saying the Russians have every motivation to turn that line off and not do anything that would delay repair.
If someone sees things differently, I am all ears. I just don't see how the Russians sabotaging themselves would appear to advance their goals, but I am open to hearing anything I may be missing.