On second thought, I am inclined to think that the Fedex have outwitted their pranksters. Albeit unconsciously. they must have felt they were somehow being toyed with and they more or less consciously accepted the kind of role playing that was expected of them. Anything that is staged, faked, can be somehow perceived by the most 'unassuming fellow'.
Always had it, always will ...and what if you have been had?