User blog comment:Morganaforever/Episode Review: A Lesson in Vengeance/@comment-5674726-20121118224151/@comment-5674726-20121119163352

If Guinevere is enchanted, then Morgana is pulling the strings and Guinevere can't be blamed.

If it's a case of Morgana influencing Guinevere's view of the world so that she sees Arthur & Co. as her enemies and Morgana as her only friend, without robbing her of all free will, then it could be argued that Guinevere bears some responsibility for how she chooses to act towards her perceived enemies.