I've already explained that I signed an NDA and part of the NDA (=Non Disclosure Agreement) is to not disclose the details of the settlement, do you want to see a bank transfer slip showing a payment was made? This I can show you but I cannot show the other things here. Nonetheless at least some other good members like the one quoted above does believe this, I have no intention of lying about it, none whatsoever.
I believe that he did actually help you get your funds back. I hope you understand the reason you're getting all these questions is because you're the only person that appears even a little credible that has come forward and said GP actually returned your funds. He's been here over 3 years. Almost 5,000 posts. And you're the only one. (Of course it's pretty clear he managed to scam you out of ~$1k USD a few months later, which ironically makes you even more credible, but that's besides the point)
My guess is that your case was one of the rare ones where a few emails was all it took to convince the Casino to return the funds. I wouldn't be surprised if he tried to appear to you as if he was using a lawyer and working with multiple people, but really it was just him trying to scare the Casino into giving you a refund, and it actually worked for once.
Did he ever have other players contact you as a reference?
Did you know the Lady that you decided to put up the money for personally? Or did Game-Protect introduce you guys and then help work out a deal so that "everyone could win?"
To be clear, I'm purely speculating here.