Not if she use her Aes Sedai mystery to make him think she would know when he lied, and used her skill in the Great Game to read between the lines to tell an obvious lie and call him on it, solidifying his belief that she can.

Maybe Mordeth is slicker then we give credit? I could have sworn she gave a disertation on what happened to Fain in Shadar Logoth, so that was in tGH or tDR??

Its in TGH ch 49. Shard.