Also, I will keep the bet such that it doesn't end before the target date or a default, and add a clause against payout-rename tricks and the likes for the unlikely case he can still push in BTC from wherever and is aiming for the sky of Bitcoin Ponzis.
Vandroiy, you've gone from a wager where the risks were known and (IMO) fairly equitable, to a wager where the risk is all on your side. Pirate can't lose: either he's stumping up 5000 btc to buoy investor confidence, or he's got nothing to fear because he's legit. Either way, your risk is higher since his is nil.
Also, if you're correct and BS&T is a Ponzi, simply having a bet against Pirate only rather than his followers will do more harm than good. The 5000 btc bet will make people far more confident of BS&T, and people will lose interest in it very quickly. In fact, after the initial publicity, I predict that people will forget unless reminded, or Pirate defaults, or a year is up without him defaulting.
I'd ask you to think twice but you're clearly going to go ahead. Folly! I say.
Shh! i like it when people throw away their money without weighing their situation or seeing it from anything but their tunnel-vision view!