I should say I haven't finished all the saga yet, but I believe they won't explain this later. When Nynaeve entered the first arc of the Ter'angreal that revealed the worst fears of the first one, the one who has a relationship with the past, she was assaulted by Aginor. Was this real? And in this case... the man was really Aginor or was a random old man and later she put the face of Aginor to her reprimed memory because he was another evil man who tried to attack her, but in another sense?