A foreign multimillionaire. Those are worth less, especially if their state owes the US some favors (or doesn't like him in the first place).
That said, sure, having $50M to return points to him being complicit -if not the mastermind- on this. Especially since I don't think we're explicitly told he was multimillionaire to begin with, just a businessman, which can even mean a guy that sells lemonade at a street corner (as long as he owns the stand).
But, and this is what I wanted to point out, returning $50M, doesn't make it entirely implausible.
This boils down to the question: can a multimillionaire ever be successfully framed for something?
I say, why not?