They could hire a good lawyer who would accept the other 50% for their attorney fees.
"hire a good lawyer"??? Are you NUTS?! No attorney ALIVE would touch that with a 10-foot pole. The attorney's company of Smiley, Dodger, Shifty, Golddigger and Jones would KNOW that the coins had been someone's "loot," that is, ill-gotten gains.
They would offer to DEFEND the gold seller...at the NOMINAL fee of, well, EVERYTHING. But maybe that wouldn't even be enough for SDSG&J!!
My 2 cents.