I'm a bit worried that a lot of the evidence for cases of suspected meddling boils down to, "because they're Russian."
edit: I added to my comment before you replied in https://news.ycombinator.com/item?id=18355858, I think it addresses your point.
It didn't take much (or any) sleuthing to discover that they're Russian government funded. At that point one has to start asking WTF questions.