While I read this post, and before I got to the grandparent comment, my reaction was "Wow, this is enough of a surprise to my current model (and most of the evidence is the personal statement of an unverified person on the Internet) that my probability of it being a fabrication is significant". I don't usually get that from a LW post.

Furthermore, the effect of promoting a fabrication is way worse for accusations of major malfeasance and racism than for most minor personal anecdotes.

(This is not saying that I think the post is probably a fabrication! I give it about a 2/3 probability of being true.)