Medical school faculty have a nonnegotiable duty to report students whose professional behavior falls seriously short of the mark. If they refrain from fulfilling this duty for fear of retaliation, the antiharassment pendulum has truly swung too far.
It is the clerkship director's role to advise students labeled gunners when their behavior becomes a problem, but changes in the larger system might help to prevent this behavior from occurring in the first place.
Specific contributions to a scientific article entitle the contributor to be included as an author; requests for authorship by those who have not made those specific contributions are unethical.