Sammy quits his job to try to impress the young girls because he "defended" them. He was doing what I like to call "showing out," which means he was showing off. His motivations were purely selfish and he lets his common sense be overrided by his desire to impress the girls.
Although defending the girls could have potentially been the right thing to do had he handled it appropriately, Sammy is not a hero in my eyes because of his motivations for defending the girls. True "heroes" do not want thanks and/or attention for doing what they do. Part of what makes true heroes, in my opinion, is a humble nature and true and pure motivations.