[It likely says something about Ishimaru's current state of mind when he allows it; normally such blatant deflection would be met with a reprimand, or at least a demand for answers, but instead Ishimaru just...returns that vague smiling for a moment.

He's not in the mood to fight tonight.]

It seems our classmates are full of surprises like that - but you're right, this isn't anything I would have expected from Togami-kun, of all people!