Commentary for Kiddushin 133:8

R. Yohanan could read this law into the mishnah’s words “in any case.” And R. Dimi who disagrees and holds that the offspring is a second degree Egyptian, following the mother, he would read the words “this is the case” as excluding the case of the Egyptians. In other cases where there is kiddushin and no transgression the offspring follows the father. But not in this case.