I think your response was spot on. I just retired from 35 years as a teacher… and saw many changes over those years. One was that no male faculty member should be alone with a female student; very difficult if you are giving private lessons (I am a music teacher). We compromised by having big windows in our doors. Another is that in any situation where conflict or misinterpretation was possible there should be a witness, and the door should be open. These are not perfect solutions, and maybe policies have changed since I retired.
As for harassment, I have two takes. Over my career 3 female students came to me with complaints they had been sexually harassed by other teachers. Why to me? I was not an administrator, and I never asked them. They all said they wanted someone to know what had happened, and that they did not want to report the incidents any further. To this day I have respected their wishes. I would certainly have corroborated their stories if necessary. In each case the faculty member continued to teach. Could I have done something to let him know he was being watched without breaking my promise? I don’t know, but I was vigilant.
I was never sexually harassed, but you reminded me of the time I asked a member of our football team to close his laptop (I was not allowing laptop note taking at the time) and he ignored me. When I repeated my request he closed it, got out of his seat and advanced towards me through the class. I said “Listen _____, please think about what you are doing. I am a 55 year old guy, out of shape, you are a 19 year old football player. What do you think you are going to do when you get up here? If you turn around, sit back down and keep that laptop closed we will forget about this.” He looked around at the 50 or so people in the class and sat down. I stayed true to my word that time, too, and didn’t report him. He ended up passing the class. I still think it was the right thing to do, even though technically he should have been hauled in and thrown off the team. Neither he or any of his teammates gave me any trouble the rest of the season.