Your interpretation and understanding of this analogy is flawed. This makes you wrong. It does not make Paul or Knight a liar.
We must interpret this passage in light of other passages that explicitly make the person, not a personification or metaphor responsible for sin. Until you see that obedience/disobedience/rebellion/selfishness/lawlessness/SIN involves will/volition, you will continue to be confused by your metaphysical sin as substance theories. We have one will, not two competing wills as people in the image of God, recreated in the image of Christ. Paul is clear that our one will yields to bodily desires (flesh) or to the things of the Spirit (spirit) Rom. 6-8; Galatians). The will, not a nebulous 'flesh' thing, is causative for choices (hence why the person is responsible and cannot blame Adam, Satan, or the so-called flesh).