Wait what?!
I just stopped after accusing Martha my first playthrough. Huh.
I did think… Well okay, my thinking about accusing Martha was at least partly: this is a diverse cast, the author seemed to care about that and make it a prominent part of each character, plus at the beginning it said racism was going to be a story theme. It wasn’t going to be the immigrant or the Black student. Martha also didn’t really make sense, but she was at least LESS nice than the other two. I would’ve picked Casey solely off of worse vibes if given the choice.
But that twist I missed? Hmm. You pointed out all the reasons it doesn’t make sense. But points for at least going for something more ambitious than I thought I guess!