except that his style was never defensive and error-awaiting.
Ok. To be more precise: it was an element that came up more. After Madrid, he deplored his lost against Nole in Rome, stating something like "I've got to do something against these guys, I can no longer just wait for errors". DelPotro and Rafa have been the first to learn.
All number ones in sport tend to develop a more defensive style. It's psychology, human nature. Somtimes, loosing #1 position is the best thing that can happen, for the athlete and for the sport.