"And who is Rei?"

Now quite honestly, since they're both Japanese and all, Izaya could very well take 'Rei' as 'Zero' and go off on some wild tangent on how that was some reflection on Yuu's personality and how he was the real wolf. Yes, Rei screwed you over one last time.

He might still bring this up later, but for now, don't mind Izaya as he fishes yet another rabbit from the desk. Even though it's kind of hard to miss, missing a head and all.