Are there Conflicts of Interest in Medicine?

I worked with a pulmonologist who would not carry a pen or rx pad with a commercial logo on it. He did not have medication samples in his office.

I am regularly fed by, and acquire my CEU's from, medical service and pharmaceutical companies. HMO's own doctors, Big Pharm sponsors clinical trials, commercial industry grant money to research universities.

Who is to say when any of these potential "conflicts of interest" will or will not influence a clinician to choose one intervention or care over another.