My favorite Jóhann story is when he had spent a year writing the score for Darren Aronofsky's "Mother" and at some point realised that the film was better with no music at all. He proceeded to convince Darren to delete everything. It takes a real, selfless artist to do that. To realise the piece is better without you.
The most important part of creating art is the process, and Jóhann seemed to understand process. The score needed to be written first in order to realise that it was redundant. So in my view, Mother still has a score by Jóhann. The score is just silence... deafening, genius silence.