Just playing the devil's advocate here, but I think he's doing fine.
It doesn't sound like the pitbull has opportunity around people (not just a rural area, but literal forest), it's burning off its energy by running around every day, and most importantly, it's not around small children either. If it "misdirects" onto another farm animal, then they get rid of the cheap pitbull.
Practically, it seems like the illegal bloodhounds costed them more livestock lives than the pitbull would.
The only problems I could see is if it the pitbull gets on another farm property, or if a hunter illegally encounters it and they get into some kind of tussle. But even then, my sympathy is limited for the hunter.