While I don't know for sure, I am pretty sure that review about this being a fake documentary is actually about the wrong documentary. I believe he is referring to another mockumentary that does mention kubrick: http://en.wikipedia.org/wiki/Dark_Side_of_the_Moon_(film)
Either way this is not supposed to be a mockumentary, whether it is true or not i don't know and actual proof is not really given but it is one mans insight and speculation but it is NOT a mockumentary. It is at least very strange and interesting. It is not a movie about science and fact but a movie about wondering what if he did have something to do with it. Some things mentioned in this movie are weird and make you ponder but overall don't bet your life on it.
Either way this is not supposed to be a mockumentary, whether it is true or not i don't know and actual proof is not really given but it is one mans insight and speculation but it is NOT a mockumentary. It is at least very strange and interesting. It is not a movie about science and fact but a movie about wondering what if he did have something to do with it. Some things mentioned in this movie are weird and make you ponder but overall don't bet your life on it.