A loan doesn't change your profit for accounting purposes - you gain $$$ in cash (asset), but have the same $$$ as a loan (liability) on the other side of the balance sheet.
I suppose that with a loan it would be transparent that the money "gained" would have to be repaid later, while in the case of a sure to lose bet, the price of the derivatives could have been tweaked so it would be apparent only later that the money would be lost.
My reading here is that the base mechanism of the trade was "DB gives X, receives Y% of X over Z years".
I really wonder what % of transactions are this sort of fee-generating trade