Actually, I think that it was someone else who used the term 'fake trans', not VS. It was used to describe criminals who pretended to be trans in order to rape women, and it was suggested that those people (the 'fake' transwomen) were so rare as to have negligible impact. The massive impact on the women who were raped wasn't taken into account, and there was something of a robust discussion about it at the time.
I know who I believe said it, but as they have not commented on this thread, I will not name them, although of course they could speak out in VS's defence if they felt inclined.