Hi, everyone, first post.
With regard to Uriel's seven words: Uriel says that Mab is lying, but we know she is incapable of lying (Mr. Butcher thoughtfully wrote us a scene in this very book in which Dresden reminds us of this). On the other hand, nowhere is it said the Uriel is incapable of lying. He certainly seems to find it distasteful, but presumably he is capable of it, especially when issues of cosmic balance are involved.
The Fallen sent Harry along one path with a seven word* lie. It seems logical that Uriel would think it fitting to give him back his free will with another (a white lie in this case, and one that gives Harry the, perhaps misguided, courage to stand up to Mab). Bottom line: Harry is wrong. Mab has more control over him than he thinks she does.
*-Btw, anyone else excited over what is, to me at least, clearly an homage to Rothfuss?
Mab cannot intentionally lie. She can say something out of ignorance. Plus she probably has bullied the majority of her knights.