My guess is he didn't expect her to be alive, much less to be back with her original face; therefore, it didn't even come to his mind that this could be her. Also, the only time he saw her face while she was Naksu the assassin was during that first battle. I don't think he had the time and opportunity to look at her face that much, much more to remember it, but as far as I remember, he definitely felt her face was familiar but couldn't recall from where...