He should have at the very least exploded on her. She deserves punishment. A casual conversation isn't gonna cut it.
Here's how it plays out:
"Fumika, tell me what you did from the first time we met"
'Blah blah blah'
"So what possessed you to do this, yadda yadda," you get the point I'm making here
This chick needs some mental reconfiguration and he is the only person she knows who can mold her back into a functioning human.