In the novel heroes, we get a different view of heroes than we do in films. In films we think of a set of features which characterize the hero. Things like special outfits like Superman or Spiderman for example. In 'Heroes', characters that are presented as heroes don't have special costumes that label them as a hero. In films there is usually a 'goody' and a 'baddy'. In the end more often than not, the good defeats the bad. In 'Heroes' it isn't like this, the book doesn't show one winner. Films often show the hero as good looking,...
Francis learns that by not shooting Larry. It can't change the past even if it might make him feel better. We also learn that Francis has to move on and deal with the past.

Cormier leaves us to decide what a hero is, maybe there are no heroes, just people that happen to be in a certain place at a certain time. Cormier may be exploring himself, he may no know, but I think he is trying to explain that there are no heroes just normal people who happen to be there. " We were only there"