A professor was berating a student employee at the DMS desk, to the point where the student was in tears and the professor had comandeerd the desk phone to call the Dean to complain.
Another staff member and I went to the desk and separated them while we sorted out the problem. The student was sent for a break, and we resolved the professor's issue, which was that she had not known the media she requested was VHS and not DVD. We checked out a player and assisted in set up and she was satisfied.
The term "Workplace Bully" was not in use at the time, but there was a fellow employee that was disruptive and abusive to their staff and others around the organization. I worked with the HR office and the chain of command to bring the behavior to a stop.