User blog comment:Xilinoc/Ch. 570 (I can't think of a witty title at 11 pm)/@comment-2211792-20140226155303/@comment-11051098-20140227191719

I support that idea. Rukia was apparently injured and knocked unconscious by the unnamed attacker, and not once since then have we seen any flashback or anything that would indicate that she even remember that moment.

It could be Guenael, making his appearance vanish from her mind after knocking her out.