According to one source I found, an un-inflated football weighs 411 grams and an inflated football weighs 421 grams. The difference of 10 grams is about .35 ounces. If the theoretical football was under-filled by 25%, that would be a weight difference of 2.5 grams or about 0.088184904873951 ounces. That would be difficult to measure on a scale in a lab under excellent conditions. On the sidelines, during a cold and wet game - yeah right. Now if the footballs were filled in a warm locker room and brought out into the cold, they might "deflate" slightly but come on. I call sour grapes on this one.