The point he's making there is, first, that the false piety and theological knowledge a Pharisee might exhibit is no guarantee of righteousness. For the Samaritan lacked that piety and knowledge but was still righteous. He's also saying that we must be concerned for our neighbor and that this does not include only those closest to us. But he does not say, and it does not follow, that we do not have any special obligations to those closest to us.