Yoko's manipulation
I think this movie shows a Yoko-centered view on Lennon.
How can you make a documentary about him and not having the other three beatles interviewed?
The Beatles era is seen only with regret (there are lots of good remarks of John about that time that could have been used, see "Beatles Anthology").
Besides, there is plenty of manipulation: for example, we see the song "How do you sleep?" (written against McCartney) and then the film shows Lennon saying "It was not about Paul, it was about me". But he's not talking about "How do you sleep?", but "Steel and glass".
Yoko Ono is a liar.