Except she didn't reject him, and he really didn't try to ruin her character. I'm not saying he shouldn't have done more, I'm saying the best he can do is give her space and time to process her own feelings, and then be blatantly, painfully honest, and get his other "friend" out of his life. There's nothing else to be done.

It's not gaslighting or manipulative to ask someone to reason out their emotional state when you're trying to apologize and have an honest conversation.