Here in the US if you have that much money you can get away with crimes you did commit.
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?
(Though this begs the question how come the real con hadn't gotten the money by then, perhaps they did it piecemeal e.g. to not draw attention, which might explain why only $50M were left).