No it's not possible to get stuck by a needle and not feel it. And besides which, it's a completely irrational thought that someone would do that so I strongly advise you not to jump down that obsessive thinking rabbit hole.
The only other thing that i am concerned about during this encounter when the guy sat next to me was that he put his arm around me and held my shoulder. I noticed some hours later that I had a small ring shaped bruise about 4 mm in diameter. Could he have stuck me with something like a needle even though I never felt anything?
Nothing you have described is a risk for HIV. In an adult the only way you have a chance for infection is by unprotected anal/vaginal sex or by sharing needles for drugs. Nothing else in an adult leads to infection. You had no risk which obviously means nothing to test.