I would call the complaintant. Tell him you are investigating the complaint. call him at work. In fact i would call his company manager, tell the manager you are investigating a compliant to the DOI. by the complaintant. Make sure you ask the manager, who is his manager, and so on.... to CC,your investigation. And of course CC, his compliance dept. (CC means carbin copy, for you youngsters), Fight fire with fire. His little funny, will back fire on him... When his company finds out he is part of an insurance investigation, it will generate reports from his company, To cover your ass reports. making everyone unhappy.