YMMV / Supergirl (2015) S2E14 "Homecoming"

• Informed Wrongness: Played with. While Alex was wrong to basically tell Kara to choose a side, keep in mind that her father just came back into her life after being gone for most of it. Now he's back, and in her mind, people like Mon-El and even Kara were attacking him for no real valid reason. Also, her emotions were clearly clouding her judgment.
• Unintentionally Unsympathetic: You're supposed to feel bad for Alex when everyone starts suspecting that her father has an ulterior motive for coming back. Unfortunately, she comes off as a major Jerkass to everyone, especially Kara, her adopted sister, even threatening to disown her. Therefore, any respect for her, including letting Jeremiah get away, is gone.
• The Un-Twist: Jeremiah being turned into a Cyborg by CADMUS was one of the most popular theories since the beginning of the series.