No, you cannot " skip HIV " and get AIDS directly. AIDS is just a condition caused by HIV if not treated in time. It isn't possible to progress to AIDS that quickly, usually takes 8-10 years without treatment. If you really have Kaposi Sarcoma it isn't because you got AIDS from your recent encounter. If you tested for HIV on the 8th week it's pretty sure you are negative.
If you would have KS, then you would have had AIDS for several years that was not treated and you 8 week test would have been positive.
Teak, I think it is possible to have KS (I am not saying he has it) without having AIDS or HIV.
It rare for anyone to have KS unless they have untreated AIDS. Those rare people that contract KS without AIDS are elderly Italian and Jewish men and then it comes on slow unlike with AIDS where it comes on fast.
Would just a HHV-8 infection have caused bad flu like symptoms that I had 2-3 weeks after my interaction with csw. Assuming no HIV becasue of my 8 week negative test?