Wet blood isn't a risk either. In order to infect a person, HIV must enter the bloodstream. That CANNOT happen through minor cuts and scrapes. The only wounds that would present any concern would be a situation in which two people have severe injuries that require immediate medical attention, and their blood co-mingles. We're talking about epic events like a major automobile accident, with two people in danger of dying from blood loss, lying right on top of each other.
Forget about events like this and move on. It is absolutely impossible to contract HIV from blood on surfaces, or by touching other people with blood or cuts on your hands.