That is the responsibility of the support and information department. One way to assess the situation is to ask the person to write down their version of the facts. It is a kind of diary where they write down the where, when, what and how. A document like that gives us a good idea of what happened.
Of course, we will have to meet with the person a number of times to listen to them and to ask them questions. We will read all the documents related to the case before we determine whether we are dealing with workplace harassment or not.
People call us sometimes to tell us that they are experiencing frustration at work, but that is not harassment.