1 bug in the The_Last_Tuatha_De_Danann quest. The bug is reliably repeatable.
When I talk to the mayor to locate Flaithbertach's grandchildren, I chose to save them by swapping them with slaves. But, when I open my "Notes on Eriu", I get this:
Note 1: You chose to kill Flaithbertach's grandchildren.
Which is strange, because I chose to save the grandchildren. If I save them without using the slave decoys, then I get the correct Note 1. I don't know if this effects the Morrigan relationship, or if it's just a simple description error.
EDIT: The bug does not seem to affect the player's relationship with Morrigan. I was able to reveal the survival of the two children to her and she was overjoyed. It seems like the bug is a simple description error of little consequence.