The pig goes in the source end of the pipeline and works its way downstream. So it would have been inserted at the Vyborg terminal.ok - but there are only two ends to this - the pitcher or the catcher. who controls each? This is a pretty major thing. what interests are served by this?
The point was that destroying a pipeline doesn't take high-tech super CIA frogmen with Jewish space lasers. It's pretty easy and there are number of ways to do it.
BTW: There was some reporting that Russian ships and/or subs were in the area prior to the explosion. I would take that reporting with a grain of salt since Russian ships and subs regularly operate in that area. It could just be a coincidence. https://edition.cnn.com/2022/09/28/politics/nord-stream-pipeline-leak-russian-navy-ships/index.html
I have no idea why Russia would want to destroy this pipeline, but I suspect it may be to force all gas shipments via pipeline through Ukraine. There is some 3D chess going on here I don't understand.