Listening is an art. To say that dynamic palpation to sense joint fixation is unreliable because of examiner variables is missing the point. For example, imagine six of the finest artists in history painting the same scene. Will the resulting picture on their respective canvases be the same. Of course not.
Painting is an art.
The interpretation is subjective and to a variable degree intuitive. Imagine six of the finest musicians in history playing the same musical composition solo. Will the resulting auditions be the same. No two DCs adjust the same way. No two doctors take a case history the same way.