There is nothing in the article, the twitter thread it quotes, or the text from Musk's biography quoted in the respective tweet, that indicates that the Koch brothers assisted Elon Musk in any way in trying to sabotage California's high speed rail. They're simply mentioned as other people that oppose transitioning away from automobiles.

Furthermore, Elon Musk doesn't say that the Hyperloop "was a conspiracy designed to sabotage high speed rail." He is quoted in his biography as saying that he hates high speed rail, doesn't want them to build it, and thinks it's a waste of money. He also says that he had no intention of leading the effort to build Hyperloop himself, where he's directly quoted as saying, "Down the road, I might fund or advise on a Hyperloop project, but right now I can't take my eye off the ball at either SpaceX or Tesla." The biographer speculates that this means it was a cynical ploy to get HSR cancelled, and I don't think it's unreasonable to infer this, but one could just as easily infer that Elon really did want the California legislature to build something akin to a Hyperloop instead.

There's no debating that Elon hates public transit, he'll tell you himself[1]. You don't have to spread misinformation to make that point

[1] https://www.wired.com/story/elon-musk-awkward-dislike-mass-t...