Dr. Ramey's specific facts perhaps are correct, but his interpretation is flawed because he is not looking at them in the larger context.
AIDS in Africa is spread primarily through heterosexual contact. If a straight person had been the first to bring it to the U.S., then the outbreak would have occurred in the heterosexual population. It was just a matter of chance.
One might even suppose that if the disease had started here in the straight population we might have been moved to study and contain it much earlier than we did.