Would you agree with the theory that had Nadal managed to win either the Indian Wells or Miami final last year, that 2011 would have turned out totally differently than what it did?
Joking aside I honestly don't know, it's a bit similar to so many people claiming Rome 2006 as a deciding point in Fedal CC rivalry.
Miami final did feel like a turning moment because Novak outlasted Nadal physically(there was that moment in the final tiebreak where Nadal bended and looked tired, that might have gotten into Nadal's head as he was the undisputed king in that department until 2011) and beat him in a thriller(match that went the distance) while as a rule all matches of that kind have went Nadal's way until 2011 IW and Miami.
However I feel Nadal did a good job in putting all those losses behind him mentally when they faced off in a Wimbledon final and started the match very strong. When he lost that 1st set while serving so amazingly well I think all he got dishearted a bit and all those lossess came back at an instant.
At USO final, Nadal looked like Fed when he played him at AO in 2009, get a lead then waste it each time, only play great tennis when behind, disappear in the last set etc. in contrast Novak was firmly believing he should win during the whole match, even when he started serving like crap in the 4th set.