The relationship failed because of a lack of accountability. It's mentioned in the article that one of the investors does not even want to pursue legal action due to his ideology, in effect letting Johnson off scot-free.
Berwick is sticking to his libertarian principals and not taking part in any legal action against his former partner
I think we can agree that this is a clear example of the frequent need of a third-party adjudicator in order to enforce honesty and reliability in transactions. Berwick is wealthy and so can afford the loss, but not everyone has a stable financial net to fall back on.