It has been pointed out that stress, such as that caused by a rape, can delay or prevent ovulation. He probably heard that but didn’t get it quite right.
And “legitimate” probably refers to the number of rape cases (the non-legitimate ones) that are buyer’s remorse followed by an accusation.
He was still stupid to put it the way he did, but not with evil intent.
A better way would have been “should an innocent child die for the misbehavior of another person?”
Does that include the misbehavior of a man and a woman who have consensual and unprotected sex, and then find the pregnancy inconvenient ?