At the stoning of the woman caught in adultery, did Jesus teach that the Law was gone, or did He criticize because the Law was not followed? Did Jesus eliminate the Law as popular church teaching suggests, or did He disapprove of the mishandling of God’s living oracles? I think in each question it is the latter. When Jesus was tested, He stayed with the Law while His opponents stuck with their own interpretations and traditions. His opponents were wrong in nearly every case.
Jesus never tells us that “we all sin” so none of us can judge. What He tells us is that to judge properly we need to stay within the whole of His Law. The people testing Jesus wanted permission to sin. They wanted certification for their self-appointed authority. But they didn’t want God’s Law. See the video for more details.