Welcome to our forum and thanks for your question.  I can understand how being spat upon for no good reason would be a memorable and worrisome event.  Having said that, I am also quite comfortable with assuring you that this sort of event would not put you at any risk for HIV or any other STI. the reasons for this are largely the ones you have already mentioned: Most people do not have HIV or other STIs, these organisms quickly become non-infectious on exposure to the environment,. and even if he did, there are just no instances in which saliva (with or without blood present) or sputum (phlegm) have transmitted HIV, hepatitis or other STIs or blood borne diseases.  Such an exposure might put you at risk for other problems such a pulmonary infections (which you also didn't get since you would have developed respiratory symptoms), but not HIV or other STI.

There is no medical reason for concern or for testing.  Should you choose to test for HIV for the reassurance that a negative test might give you, I am confident that the result of testing would be negative.

I hope my comments are helpful.  EWH

Even with broken teeth or gum disease on your part, or blood in the spit from the person who spat upon you, there would be no risk whatsoever.  Still nothing to worry about from  a medical or scientific perspective.

Your question, the fact that this has troubled you for two years, and your follow-up question all suggest that this is prominently on your mind, as such, I wonder if you should test in order to put your fears aside.  I would only recommend this if you felt that you would be able to accept the results and, when they are negative, move on without further concern.  EWH