Pirate is in debt service default of his own contract.  By the rules of this forum he is a scammer.   

He owes forum members in excess of $5M and has not repaid that nor provided any transparency on how/when he intends to repay it.   
His obligations are increasing at a rate of $57,600 per day. 

I mean by your logic as long as he never admits to it being a ponzi he simply can never pay anyone back ever and it isn't a ponzi or a scam. 
There may never be absolute proof baring a confession.  To be convicted in a criminal court only requires "proof beyond a REASONABLE DOUBT", in civil court is merely requires the "preponderance of evidence".  Yes based on the facts known unless Pirate provided additional evidence to his defense he would lose a civil case alleging fraud and running a ponzi scam.  Pirate is certainly free to provide evidence to his defense.  He has chosen to provide nothing, and not repay more than a token amount, provide no specific timelines on repayment, and is in default of his own contract.

THAT IS A SCAM.  PERIOD.