It wasn't just this post, it was all of them (at least, all of them that make their way to HN). But I suppose I will need to update my priors since if this post is vouched for, it should make the other posts more likely to be true rather than less likely.
Rachel's posts have a thin veneer of pseudo-anonmyization that makes it not blatantly obvious which company each story is from, but I can vouch for a decent number of stories being basically spot on what happened (with a little bit of editorializing around the why things happened the way they did).