Both children were the wrong one to abort.
This headline implies that it’s horrible that the one kid was aborted, but if the other had been, it would have been ok. It’s not really a horrible mistake. With the “mistake” or not, one child would have been aborted. It was a horrible choice to abort one child in the first place.
The right one to abort (after a trial, of course — I'm not advocating vigilante justice) is the doctor if he is convicted of premeditated murder.
Even today, least in some American states, the “emergency C-section” followed by killing the second baby outside the womb might still result in criminal charges. Biblically and morally, there should be no difference between killing a pre-born baby and a post-born baby, but at least today many Americans still understand there is no difference between killing a baby five minutes after birth and five months after birth.