Here's the dialogue:
"I want the Exchange to stop meddling in the Ithorians' restoration effort."
"Why would I want to do that? The Ithorians are ruining my profits."
"Because I asked you to?"
"Come now, surely you can do better than that? The Exchange isn't trifled with lightly."
"Better? Look around, you saw what I did here."
"I suppose you do make a bit of sense there. Fine, I will allow the Ithorians to do their business, but listen to me when I say this."
"The Exchange is not bullied. If you push, expect to be pushed back."
It doesn't really specify leaving the Ithorians completely alone, just not interfere in their business on the restoration project. And he is a crimeboss.
Like I said, it does make sense to me, and it was OE's intend to boot...
But I would be willing to hear from more users what they think...
EDIT: It would make sense for the exile to card the Ithorian on while doing this deal (and have a persuasion check to check the result), but sadly, there is no content for that, so no part of the TSLRCM.
But if you want, like I said, I could wip up a mod that does that in about 5 min or so...