Why invent something if Liz Truss turned out to be not only an incompetent politician, but also a complete fool? Plus, the operation did not go exactly according to plan and the explosive charge did not work on one of the branches of the gas pipeline - therefore, investigators from Sweden had to clean up traces and classify the results of the investigation for several weeks before allowing Russia to the scene.
So now Sweden is in on the "conspiracy" too

Meanwhile in the real world suspects and random conspiratards usually aren't allowed into crime scenes. Once investigators are done I'm sure Putin will be given a folder with the results. Possibly redacted a bit to not harm his fragile ego.