It sucks that you were criticized for doing a good deed :( Hopefully this doesn't stop you from helping other people in the future! It's okay OP, you did the right thing!
Natural selection involves nature "selecting" those genetic traits which help an organism survive in its environment the best, while also taking into consideration the fitness of said organism.
-An evolution student
@12. No. Human selection, or selective breeding, only occurs if there is a systematic attempt to encourage or discourage specific traits. In this context, early domesticated plants and animals were initially the product of natural selection with selective breeding only occurring relatively recently in history. One person pissing off another person enough for the second person to push them into traffic would count as natural selection, if it happened enough without a systematic effort. Oh, and also as murder.
I say it was natural selection for the car to hit her, OP interfered and this pushing her back into traffic would be correcting the artificial selection and puts it back to the original selection category.