The sale was a naked short. The seller had no gold to sell. COMEX reported having gold only equal to about half of the short sale in its vaults, and not all of that was available for delivery. No one but the Federal Reserve could have placed such an order, and the order came from one of the Fed's bullion banks, one of the entities "too big to fail."
Bill Kaye of the Greater Asian Hedge Fund in Hong Kong and Dave Kranzler of Golden Returns Capital have filled in the details of how the manipulation worked. Being sophisticated investors of many years of experience, both Kaye and Kranzler understand that the financial press runs with the authorized story planted to serve the agenda that has been put into play.