The validity of the theory he mentioned is irrelevant to the point he made which is: abortion is unacceptable in the case where rape is not a factor.
I thought his point was that abortion is not the answer in the case of a rape pregnancy, and you seem to be saying something different.
In any case, I acknowledge that whether or not mentioning the low probability of getting pregnant from rape was wise is debatable. But that is a separate issue, and one which I really have not addressed. My interest in this is mostly trying to educate people on the science.