Air inactivates HIV to add to Curfew's list of risks, so this would not be a way that anyone would ever get HIV.
The only risks for HIV in adults are:
1) Having unprotected anal or vaginal sex, or
2) sharing intravenous needles with IV drug users.
Touching blood or other fluids on surfaces or fabrics is NOT a risk for HIV. You will never get HIV in a bathroom unless you have unprotected intercourse with someone, or share intravenous needles with someone, in the bathroom.