[He's finding it strange that Otonashi would feel any pain at all, buuut there's no use questioning these things.]

You could even say that it nailed you, I suppose. Ha ha! [He couldn't resist. But he'll at least try to be helpful by picking out a few uniform-looking blazers and draping them over the racks for Otonashi to give a yea or nay.]

But in all seriousness, that's a bit too dangerous a prank for me to condone.