You're right. They look dazed and confused. Racists are blind to history too.
I can't say about the particular student, but the racism is bascially built in. I can't imagine that those kids would have tried to pull that shit if there were any black people around or if they let them in the greek system. And yes, for most of those girls, getting that close to a black man would get them kicked out of the house or the family. I'm not exaggerating--once again, my students' writing is an incredibly rich source of ethnographic detail. A female student this semester wrote a paper in which she said it finally dawned on her when she came to college that it might be okay for other people to date people of other races. It's not for her of course . . .
Needless to say, one of the big reasons the greek system remains segregated is b/c the alumni threaten to withdraw funds from the university and the frat/sorority if they integrate.
I recently forthrightly suggested to a former student (one who has the ability, if not the propensity to understand arguments) that fraternities on campus were racist to the core. He said that they didn't prohibit black members in prinicple. I asked him if they had ever co-sponsored an event with a black fraternity (as they do with white fraternities all the time). Blank stare. I asked him how many of his frat brothers had "little sisters" from black sororities. Hasty departure.
Christian