People who are genuinely pro-life understand that this very much is a black and white issue.
Unless ALL human life is sacred, ALL are vulnerable. We have seen this again and again throughout history.
And, for the record, I have met Dr. Carson and am extremely impressed with him on nearly all other issues.
I am even prepared to give him the benefit of the doubt and say that perhaps he misspoke or that he held positions in the past that he no longer holds. However, IF this is the case, he needs to explain his evolution on the matter and what he really believes. I've found that those who are genuinely pro-life are quite comfortable doing this; but those who are claiming to be pro-life for political convenience are constantly making blunders that reveal their true position (look at Mitt Romney).
“I am even prepared to give him the benefit of the doubt and say that perhaps he misspoke or that he held positions in the past that he no longer holds. However, IF this is the case, he needs to explain his evolution on the matter and what he really believes.”
I can see no valid reason to impeach your logic here.