This is the great question!
Really I think it is a fake documentary, I do not know why this man would like to be filmed while he is deceived. Furthermore, the end is too much « American », why in most American movie production there are always people who have a hard life, or a important disability a very sad end with lot of ingredients to have pity (mercy).
maybe I am nasty, but usually American people go to the court for less than this story.
The facts are this guy Yaniv Schulman is photographer and this « documentary » is a very great publicity stunt for him and his enterprise. He has now 10 149 friends and Catfish movie has 51 084 friends on Facebook. And to do not know if it is a documentary or not is a good way to promote the « documentary ».
You can find lot of discussion about the reality of the falseness of the documentary:
« Inspired by the debunking of the movie CATFISH. This site is set up to be a catfish catcher. A CATFISH is someone online that is misrepresenting them selves as someone else. If you find someone or something online you think is a misrepresenting catfish. »
They say it is a real documentary and laugh when people say the opposite.