so it seems like he ended the BCST with ~ 500k hard BTC in a wallet. Now remember he paid a shit ton of interest, always depleting principal week after week - so that means he may have collected ~ 700k BTC and paid out ~200k BTC over time and is left with ~500k BTC.
I don't understand why you assume that it belongs to Pirate in the first place? If it does it would mean he actually has about the required amount to pay out, and he made it with pretty much all of the money he collected just sitting there doing nothing. That makes no sense.