(Later on Foul might be talking about Jeremiah, but here he's talking to Herem about Joan, and why would Joan be concerned at all about Jeremiah?)
Still, I think the argument that Foul sees lies as beneath him is worth considering. (It doesn't exactly fit with him getting himself onto Kevin's Council, but maybe that could be explained by them being just innocent naifs who don't really know about Foul and so he tells them things that are true, but not enough to trigger warning. Come to think of it, I could see Foul laughing his heart out about that tactic.)
I guess I have to go re-read and look at the later passages. Oh, joy
