If I understand your question correctly I think Jim Willie answered it in a manner of speaking.

He said that the Shanghai exchange may soon put a price on gold at their exchange of approximately double its current price and they will reprice silver to approximately 1/25 the price of gold. They would both buy and sell the physical metals for that price. Anyone could now make huge profit by buying from the COMEX or LBMA and selling on the Shanghai exchange.

The fact that no one will do it (or take advantage of the price differential) is evidence to the world that they cannot get delivery from either the COMEX or LBMA to take advantage of the arbitrage. He believes that this will be the method used by the Shanghai exchange to reveal to the world that the COMEX and LBMA doesn't have the goods they say they do.

If those exchanges did have the metal and they had continuing supply they'd be fools not to take advantage of it themselves.

P.