Late in my first year of grad school, I was tasked with showing a possible applicant around the college. One of my friends at school heard he was applying. She knew him from undergrad and told me he was a nightmare but didn't go into specifics. Since I worked directly with the head of my department, she pleaded with me to tell them to reject this guy from the school. Even before she told me about him, I could tell from my brief interaction with him that he was prick, but I didn't feel comfortable going along with that. His application got approved.

Cut to a year later, me and her are having to file detailed harassment complaints against this guy because he was indeed a nightmare. The school put him on probation. He kept causing all sorts of problems for me, her, and other students. I really wish I had listened to her.