Air inactivates the virus, and this is why only the head of the penis needs to be covered. Lots of people have this concern but this is not how people get HIV. Since your sex was protected and the head of your penis was covered, you should be protected from transmission of the virus.
HIV can only enter through the urethra so no condom movement is possible to expose that. It is effectively dead in air otherwise we would all have it from rashes and cuts rubbing the wrong person's rashes or cuts.