What exactly does it take to have knowledge of the existence of a threat? In the case that has provoked all of this, there weren't any warning signs of impending doom. It therefore seams reasonable to me that nobody can know if a threat exists or not until after-the-fact. If it's unknowable, then what's the point in bringing it up anyway?
More importantly, this isn't an academic point. Feelings can't be invalidated. It doesn't make sense to speak of feelings or perceptions as invalid or valid---they simply exist in our minds. Perhaps they will go away or subside with more careful reflection and discussion, but that doesn't mean it is somehow invalid to acknowledge them. Particularly in this context, where presumably, this feeling was fostered by the recent kerfuffle.
The only thing we can say about the validity of the commenter's feelings or perceptions is that either they are truly what the commenter believes he felt, or the commenter is lying. The first is the only useful assumption given what we know; so we go with it.
So what if the commenter escaped without any public shaming? That has no impact on the commenter's feelings or perception at the time and therefore is missing the point of the commenter's reflection.
I still don't see any impending doom. Her original photograph tweet was retweeted... 20 times, I think? The only reason that guy was fired was because it was featured on HN through no action of Adria's.
Anyway, I'm saying that someone who would feel threatened by accidentally assuming a male gender might not necessarily be on their side, and their assumption might just be misguided. That invalidates the rest of his post, since it all relied on him feeling threatened when the threat doesn't exist.