One thing that struck me about the movie was how at certain times the rhythm and speaking speed were much quicker than at other times. This could be due to the fact that the original version of the movie was closer to four hours than the final cut of around two hours, however I think it comes from something more pertinent to the theme of the movie.
Scenes that involved the family and other, more simple, parts of the plot line, had “normal” rhythm. By saying this I mean that the people talked in a conversational tone at a relatively normal speed. However looking at more tense scenes, or scenes that begin to reveal parts of the truth, the speed of the speaking becomes quicker. One place where this was apparent was in the park in DC when Garrison is listening to the mysterious Mr. X. The more into the story Mr. X gets, the quicker he talks and the harder it was (at least for me) to follow him. I think that this may have something to do with how the truth is found out. Oliver may have had these scenes said in a rushed tone to portray that the truth is not always easy to follow, and finding the truth can sometimes be confusing. Or maybe he was just trying to fit as much of the movie into as little time as possible. Either way it is something to ponder.