Social issues can happen in the workplace, no matter how positive the company culture. We are dealing with human beings, after all! The interviewer wants to know if you have exposure to the stress and discomfort associated with workplace investigations. Whether you have this experience or not, you can display to the interviewer that you are well-trained in professionally handling employee grievances and official complaints. Show that you take these situations seriously. If you have HR training related to discrimination, bullying, or harassment, be sure to mention the details of this formal training.