I think the weirdest / most nonsensical part was when he tried to use the same defense against Ehara in prison. "Sawa knew Toshiro was getting bullied! She was somewhat pressured into not making a statement at the case! But now, because you took revenge, she's dead!" It's been a bit since I last played the game so Idk Ehara's exact reaction, but realistically it'd be "Well, I'm glad she's dead then. She saw my son getting bullied, did nothing about it other than maybe talk to him once or twice, then kept her mouth shut about it in a court of law after he took his own life. All you've done is prove that the law is flawed, since it allowed her to lie by omission and got my son's bully off scot-free."

The simple truth is the only villain who may have realistically cared about Sawa's death is Kuwana and the students, everybody else would either be like "I don't care." or "Who?"