Maybe did the US only supply a few (hundreds...) pies, for some brass to drop it down before abandoning a location, for the Germans to find it and become discouraged.
It seems that in ancient times some town besieged for quite a long time was starving but did throw away munificent food, simulating neglect, in order for it to fall on the attackers, who (not eager to maintain camp for long) promptly packed up and leaved.