One of my dorm mates, an African student, had her boyfriend stay overnight often. He used the shower in the dorm. My dorm mate's shower rack where she puts her towel and bath stuff is right next to mine. I found tightly curled black hairs in my towel. It could only be from an African.
I confronted the African student and told her to ask her boyfriend not to use my towel. She said I had no proof. I told her I found curly black hair in my towel, and I didn't know of anyone else around who could have that hair except him. She said this was a racist claim.
I ended up not keeping my towel in the bathroom.
There was a white guy who went to a Chinese restaurant, found a hair in his food, and complained to the waitress. The waitress pointed out to him that it was a blond hair, and since no one in the kitchen had that kind of hair, it could only be his own. Of course the white guy promptly shut up.
I don't see any problem with using physical evidence to prove or disprove something. So physical evidence sometimes happens to be related to racial characteristics. Does that mean using this evidence is racist? I am tired of people like that refusing to take responsibility for their actions by hiding behind the claims of "racism" when someone criticizes them. It only takes away from the credibility of people with real claims of racism.