I would appreciate more detail on how they determined whether people were lying or not, especially considering there would be no advantage to lying since the article mentions that self-identifying men were permitted to attend the event.
Yeah, that's extra sketchy. Gives me more of the impression that by "female and non-binary" they meant "cis women and some enbys & trans women IF they dress up feminine". In an event that doesn't bar men from entering, why would any guy lie about their gender identity? What's the prize, getting to enter a convention that you could have entered if you didn't lie anwyays? As a trans woman that still presents masculine and has not started any HRT, it wouldn't be the first time someone assumed I was just lying about my identity to... I dunno, score brownie points I guess?