so he isn't the real Kudou but he doesn't know he's a clone and kujirai is also a clone but she knows?
Also I feel like it was probably an accident that he blames himself for
I don't have it in me to be "shocked" by this because it explains so little about what actually happened, and completely leaves open the possibility that he simply blames himself for her death for one reason or another. So very little was actually revealed.