This means that you will see a complete divergence: GLD goes to pennies while bullion premiums go through the roof. The officially stated price doesn't even have to rise for that to happen. In fact, that will serve to keep those oblivious to these activities still in the dark.
How does this happen, exactly? The GLD trust moves physical unleveraged, unencumbered gold, as I'm sure you know. So how could its price diverge from physical for more than however long it takes to ship gold? Or are you raising a more fundamental issue with confidence in enforcement of contracts, etc, that could arise in a scenario where fiat/existing-monetary-system really starts breaking down?