There's only two things that I can think of at the moment, but I won't be surprised if there are other issues some of you might dream up.
First, I strongly doubt that TN will say anything to Marcone about assaulting Arctis Tor. So when Mab decides to get payback against the spiny demon, I doubt Marcone will see it coming.
I would guess that TN would rather not talk about Harry kicking his ass and leaving his former host a complete mess. However, even though Marcone didn't witness the fight in the Shedd Aquarium, I wouldn't be surprised if he noticed how badly Thorned Namshiel's former host's body was torn up after the denarians returned to Demonreach. Though Marcone might feel it's both natural and necessary to ask the denarian for some details.