The author is under a misconception as to the role of futures markets. Selling "naked short" contracts is what COMEX and all the other futures markets is for. The regulation he has fixed upon relates to forward physical/OTC contracts.
While I can only guess why DB were so massively short of the market, picking up the gold from a Central Bank (probably leased), to fulfil the contract, is routine, although the size of the transaction is not. "Any economic unit can emit money. The serious problem is to get it accepted" Hyman Minsky
