Unless the writers want to put themselves in the bind Supernatural did--they're wanted, no they're legally dead, no they're legally dead and wanted--they have to con him out of trouble. Nate Ford the fugitive would just be a whole different show. I think we are going to see Nate embrace his new identity of thief, but Rogers et al are pretty good at slow build up on that sort of thing.
Sterling holds the cards, so they have to give, or appear to give, Sterling something he wants more than winning the case against Kadjic. I guess the question is, what does Sterling want? I think he wants to hunt Tara Cole in a cat and mouse game that takes them around the world, new next fall on TNT, but I could be wrong.
Did Sterling ever have direct interaction with Tara this season? It would be interesting to see how that would turn out, though I doubt the crew would sell her out. They owe her- even though she got paid- she went above and beyond quite a bit. Heck, even Parker trusts her a little- death threats and all.
One of the reasons I seriously love Sterling is his insane ability to get away much better off after each and every interaction with the Leverage Crew. Promotion after promotion; I think the last we see of him is when they finally take him out. Though I have to say I don't really want that day to come soon ;p
They use a doppleganger that they claim is the real Nate (massive DNA scam, methinks), but who then gets let go when it turns out he's not (duh!) the real Nate. By then the real Nate is off somewhere nice sunning himself with Sophie whilst Parker is working her way through the tourists pockets/bags/rooms, Hardison is holed up in a hotel room making them up all new id's ("grumblegrumble always stuck indoors grumblegrumble hate the sun anyway grumblegrumble") & Elliot is drinking the days away hitting on anything that moves, including Parker (accidentally, of course - "what? she looked hot from the back, where I couldn't see all her crazy").