It doesn't matter whether the person had a high viral load or not, or whether they were on treatment or not. You cannot get HIV by touching blood, even if you have cuts or scrapes on your skin. Blood, once outside of the body, is no longer infectious.
The only risks for HIV in adults are:
1) Having unprotected anal or vaginal sex, or
2) sharing intravenous needles with IV drug users.
If you don't do either of those activities, you will NEVER have to worry about HIV.