Different Realtor Associations may have variations on procedures, but ALL Realtors subscribe to, and have taken an oathto uphold the Code of Ethics. A Realtor is a licensee who is a member in good standing with the National Association of Realtors, as well as a member of the Realtor Association in your state and your region. Not all people who are licensed in real estate are Realtors. Assuming the agent in your question IS a Realtor, then here's a probable list of actions that will occur after the local Association of Realtors receives an ethics complaint from either a member of the public or another Realtor about another Realtor(s):
The person making the complaint is sent proper forms to fill out stating about whom the complaint is being made and a copy of the 2009 Realtor Code of Ethics. The Complainant is asked to list the Article(s) the Realtor may have violated, reasons why they think there was a violation (i.e. what happened) and any supporting evidence the complainant wants to add to support their claim.
The Association will send a copy of the complaint to the Realtor in question (called the Respondent) who will be served notice that a complaint was made and to make a formal Reply to the Association as to the charges made, as to the facts as stated by the person making the complaint and to add any supporting evidence (s)he may wish to add.
Once compiled, the case goes before a screening committee, called the Grievance Committee, made up of Realtor members of that local Association. Their job is to view the case, the evidence presented by both parties and to decide if a POSSIBLE Code of Ethics violation has occurred. If not, the case dies there. If so, then the case is moved up to the Associations "Supreme Court", called the Professional Standards Committee (also made up of Realtors, but they have to hold a Broker's license, be approved by the Board of Directors and have substantial experience and a spotless record). A formal hearing date will be set and both parties will be asked to appear with any witnesses, possible attorneys (not too often but it's their right), any additional evidence and to present their case before the hearing panel. In cases where the person who made the complaint cannot or will not appear before the Professional Standards Committee to make their case, sometimes a member of the Grievance Committee will carry the complaint and the case forward to the Professional Standards Committee for the original complainant).
The Professional Standards Committee will hear all evidence, testimony and cross-examinations; will ask any other questions rthey deem appropriate to the case, then will adjourn the hearing. They will meet in Executive Session to render their decision. If found guilty of an ethics violation(s), there are several penalties the Professional Standards Committee can impose, subject to the approval of their findings and penalties suggested by the Association's Board of Directors.
It is a formal process with real consequences to offending Realtors. These matters are taken seriously by all parties. One bad Realtor can reflect on all Realtors- and the Code of Ethics is designed to protect the public and to set standards of behavior expected by ALL who carry the Realtor membership designation.
The local Association will be happy to guide you through the process and will answer all questions you may have about the process and what you need to do.
If you feel a Realtor is guilty of unethical behavior, DO NOT hesitate to lodge a complaint. Realors who have worked hard all their professional careers want offending Realtors to answer for their transgressions as, believe me, they are in the great minority.
For your convenience, here's a link to the Code of Ethics on the Realtor.org web site.