People have been wondering about that forever.
Not one of the many (1,100) women Magic had sex with has ever been known to have HIV. The woman who supposedly gave him the HIV has never been identified. It is quite a mysterious case. There were rumors that Magic was bisexual for some time before he came down with HIV. Yes, Magic was having sex with all sorts of call girls and sports groupies, but so were many of the big stars in LA in sports and entertainment. People discussing his case often note this. “Even though so many other men were doing exactly the same thing that Magic was doing with women, only Magic got HIV,” they note, leaving the implication up in the air. “Now why is that?” they ask. Rumors continue that he got it from a man.
On the other hand, Magic’s case is said to be so mild that even after all these years, he has not yet started on HIV drugs, and this is said to be compatible with his having gotten it from a woman because it is thought that female-male HIV transmission is so difficult that even when it does occur, the mode is so inefficient that the man only gets a weak dose of HIV.
People do not understand viruses. It’s all about viral load. You can be exposed to HIV and not get it, and in fact this happens all the time. If the titers are low, it simply will not transmit. This is the case in saliva. Yes there is HIV in saliva, but the titers are 99% lower than in semen or blood, so it is effectively impossible to transmit it.
There is also some new thinking that female-male HIV transmission is so weak that the man may require multiple dosings over a period of time in order to come down with HIV. In other words, he could get a bit of HIV each time he has sex with her possibly via vaginal fluids, but the titers are too low to infect at each time. However, with repeated dosings of low HIV-titer body fluid, perhaps a high enough level is built up that a threshold occurs beyond which infection can occur. But in this case, the mode was so inefficient and even the contracting dose or doses so weak that the theory is that the man may only get a weak HIV case.
And yes, your HIV case does depend on your viral load. With a low enough load, one may have only mild symptoms and may survive for decades, but with a high enough load via a very effective mode of transmission, HIV can kill you very rapidly, even within a year. Such cases continue to occur. Many such cases occurred in the gay porn industry and continue to occur to this day, especially among the “bareback” stars. HIV is so prevalent in the gay porn industry that I am not even sure that they test for it, and they let a lot of HIV-positive actors work anyway. Apparently if you fired all the HIV-positive gay porn stars or required only HIV-negative gay men to work in gay porn, you would not have much of a gay porn industry anymore.