How you can tell it's not an Indie film....(spoilers)
While the movie has many Indie film characteristics: grim, graphic reality (e.g. excrements of the old man); character development etc... The ending betrays it has been distributed by a Major Hollywood studio (and the fact that the homeless man never seem to die): the "good" guy wins and is alive - the "bad" guy (and girl) dies. When in reality it's the other way around (except the "bad" guy and girl get punished).
I don't think a movie need to follow the real events to the letter. But for goodness sake why fake out a "happy ending". While major studio produced "Into the Wild", yet they did not have the main character survive and run to embrace his "Mommy". I guess a director like Sean Penn will be less compromising when it comes to happy endings, even when demanded by the Hollywood. Alas Stuart Gordon is more about sensational thrills than the integrity of the plot.