The picture emerging of this girl is a quirk chungus, derpy hicklib who, based on her morphology, has a rather masculine disposition.
It's probably because of said disposition that she misread female social dynamics and expected there would be no "slut shaming" from the sisterhood if she did something sexually adventurous like an orgy.
The fact that she thought the men involved were gay/bi was added lib status, which as a pride "ally" she must have assumed would especially protect her from social shame – when she first noticed people were speaking negatively of the act, she text a friend words to the effect that this was part of the sexual liberation movement and "is going to become more common"
The timeline then seems clear: she was disinvited from a Halloween party because of the reputation she earned as a slut, which she then realised was a view not confined to bigoted men. When she read a comment of someone saying she was raped, she must have immediately clocked this as a possible out to absolve her of accountability and regain her social status. In her own account, she had never conceived of it in this way until she read it from someone else.
At that point, members of the sisterhood encouraged her suggestions that she was not actually responsible for anything.
"Slut shaming" still exists among sexuall liberated women, but it is at odds with their professed beliefs about sexuality. Women are expected to pick up on this nuance and push for as much female power as possible while also enforcing shaming to discourage any individual lowering female sexual market value through extreme promiscuity.
But, the sisterhood has also built an out, and now any woman can just withdraw consent reotrospectively, undo the wrong, and receive an even greater status as a victim.
The Cornell woman is ugly and also extremely boring holy shit.