Get a loan from a bank or set of banks for as much as you can. With $500k in hand and a reasonable financial situation, it should be possible to convince them that you can pay off a loan of $500k! Pay off the mafia with that; this is a near-guaranteed way of paying off the debt.
Then Smith’s bankrupt and just defrauded a bank for $500k and will face the consequences of that, but he’s still alive, with much higher probability than 50%.
Re: Doug -
Get a loan from a bank or set of banks for as much as you can. With $500k in hand and a reasonable financial situation, it should be possible to convince them that you can pay off a loan of $500k! Pay off the mafia with that; this is a near-guaranteed way of paying off the debt.
Then Smith’s bankrupt and just defrauded a bank for $500k and will face the consequences of that, but he’s still alive, with much higher probability than 50%.