(Even if she has concrete evidence Dana being sent home was actively harmful to Dana – and I don’t think she does – the way you make sure your ex-friend knows she fucked up is NOT ‘harass her in the cafeteria like a petty middle schooler repeatedly, nine months later, with maybe one veiled comment about the actual issue.’) Given the going out of her way to harass Sarah, she was definitely in the wrong there. She was definitely the wronged party in the Jacob issue.
