The WWII Draft Card Registartion information online at this time is known as the Fourth or Old Man's Registration and only required men born between 1877 and 1897 and not in the military already to file. So there was no way there can be a mixup as the son being born in 1925 would not have filed such a card nor would he have been allowed to.
Also as with the WWI Draft Card Registration, the WWII was just a registration for the Draft and did and still does not mean any man will be or is "drafted". Google "Draft Card" or "U.S. Selective Service" to clarify.