Fain, Fal Dara, and the Horn

While RJ has said that Fain was released by a Myrdraal from his cell in Fal Dara, it is unclear who led the release.  It is assumed that Ingtar did, but that seems logistically difficult for two reasons:  1. The slaying of the guards at the Dog Gate, to allow in the trollocs, would have had to have happened close to the battle; and 2. Ingtar's meeting up with Rand and taking on a Myrdraal while Rand is on his way to the dungeon. The other obvious suspect is Liandrin, who has been set up by RJ as a DF, working her DF ways, throughout the passage.  However, if it is her, why have Fain say "Oh, its you.  I wasn't expecting you" and not identify her?  Looks like misdirection to me.  It seems that there is more

It also seems likely to me that there were two seperate things going on:  one, to take the horn, and 2. freeing Fain.  My question is, were they directed by the same DF, or were they seperate goals?  Fain slays the Myrdraal with the horn to take over that group, so it seems to me that they were two seperate events.  Who directed them, if there were two?  Who directed the Fade to write the Dark Prophecy on the walls?