I think the Cain flub can be explained entirely by politician-itis combined with lack of preparation.

He wasn’t prepared for the question, so instead of giving a straight answer, he punted (as politicians do). Then, once he’d been briefed on the percentage plays, he “clarified”.

This tells us that he isn’t very well prepared (which, gosh, he’s only running for president, let’s not be too hard on him) and that he’s yet another pol who will say anything to get elected.

It tells us nothing about his personal beliefs on abortion.