To anyone wondering, I did report it and the admissions office behaved incredibly well with the information. They not only apologized numerous times (which was not needed; I understand that they can’t control what happens in interviews of course), but they thanked me for making the decision to speak up, gave me a phone call, and even a phone interview with an extremely sweet (and definitely better representative of Brown) alumna. They told me that had I not spoken up, they wouldn’t have known, and then further thanked me when (after asking the other students who were interviewed by the same guy) they found out that he had said the same things to other students. I’m really glad to have given these other students a second chance for a good interview as well, since I’ve definitely been there!
If you have an extremely strange and odd interview (to the point where you couldn’t even count it as an interview) for any university, I would say report it - and through your college counselor as well to make it more official. It doesn’t affect your chances of admission at all, and you get a second opportunity for a real interview as well - and maybe even help other prospective students who went through the same thing a second chance :))