It was only in the 1920s that the demographics, there, changed. And in the past few decades, whites have been moving there, so it's now quite a "diverse" neighborhood.
And since he teaches in Jersey...what was he doing in Harlem anyway, don't the have burger joints in N.J.?
He said he was doing takeout, so seems pretty obvious that he lives in Harlem, commutes out to Rutgers. In other words, he’s made a point out of being a white guy living in Harlem. A perfect case for someone to start feeling that white guilt!