While I applaud your disclosure Dr. Stern is both you physician and your client and therein lies the basis of bias.

You like him because he is your physician and and have a good relationship with him.  You also like him because he is your client and a source of revenue.  There is nothing wrong in this but it does raise the possibility of unconscious bias just as Dr. Stern may or may not be unconsciously biased in his medical assessment of opioids.

I would agree that Dr. Stern should not be impugned for his beliefs but neither should he have been allowed to participate where there is the appearance of bias.