He’s a professor at Columbia Med and hes the director of a cardio unit at a big hospital in NYC. That’s something.
“Oz has been a professor at the Department of Surgery at Columbia University since 2001.[24] He directs the Cardiovascular Institute and Complementary Medicine Program at New York-Presbyterian Hospital.[25] His research interests include heart valve replacement surgery, minimally invasive cardiac surgery, and health care policy.”
https://en.wikipedia.org/wiki/Mehmet_Oz#Controversies_and_criticism
On his TV show Dr. Oz also promotes homeopathy, faith healing and psychic communication with the dead, transcendental meditation and riki therapy and "miracle" weight-loss products among other questionable advice.
https://www.livescience.com/50576-dr-oz-miracle-claims.html
He may be a talented thoracic surgeon but that doesn’t make him qualified to conduct a clinical drug trial. My former orthopedist was one of the best in the country but that doesn’t make him qualified to do open heart surgery. YMMV.