The kanji is different, and for native Japanese, that is actually a big change.
That, and Tatsuya sucks at normal magic, so he isn't really a suspect for being a part of a top magician family. He is becoming famous for suppressing others without magic, after all. I guess he balances out Miyuki's overwhelming talent, making that look like an accident.
I agree about this episode being quite weak compared to the earlier ones. They just infodumped on us, something I usually dislike especially in VNs.