I assume that they were getting played and at some point wised up, either with Bran's seeing help or on their own. I mean you have an assassin blinded by revenge and a Lady of the North with barely concealed ambitions who both know better than to trust LF but they have to fight through their own baggage to get there. Considering the "trial" scene and "evidence" I would lean to Bran filling them in some and turning the tables. Not having them wise up would have pushed the WTF more than this because the dude sees stuff (even if he does not seemingly know what to do with his information at times).
Like Bran suddenly hitting onto "Oh, boy, you know what, Jon needs to know this!"