You see a patient who comes to you and reports that another surgeon had bad things to say about you; how do you respond?
"I suppose I have some choices here. I could confront the person and ask for an explanation; I could report him or her to the state medical board; or I could ignore it. Of these the only smart choice is to ignore it. The other choices are emotional knee-jerk reactions fraught with downsides."
"Such things are hard to prove, and I have also learned that patients sometimes distort their memory when angry with a previous doctor and don't present an accurate story. Sometimes they might even try to drag me into their disagreement with that doctor. Even if they are reporting something like this accurately, the fact that they're seeing me already means I have nothing more to gain by gainsaying against that doctor. My patient can only see that as my being professional and the bonus is that I am not dragged into some flame war where there are no winners."
Anyone can be a jerk, even a doctor. Yes, this is unethical, dirty politics, and an ugly side of competition. It may even be due to some personal issue you don't even know about. You can rest assured that you're not the only person on this doctor's 'hit' list. Hospitals don't want people like that on their staffs, but if you respond in kind, you'll be lumped together with the original culprit. You just can't go wrong being a gentleman (or a lady). It's not being a patsy, it's being smart, because the interviewer will see that you're above such things.
"That would be unfortunate, but there's really nothing I can do about it except carry on without reacting and continuing to do the best work I can."