I assume the USADA is stating that all these tests we wrong ? Or that his 'doping' technique was too advanced ? Seems a pretty long stretch of the bow in my mind.
A new process made EPO widely available in the late 1980s. But because EPO is chemically similar to substances the body produces naturally, nobody was able to come up with a way to test athletes for EPO usage at all until the year 2000 (http://www.wada-ama.org/en/Resources/Q-and-A/EPO-Detection/), and it took a few more years after that for anti-doping agencies to have confidence in the accuracy of the test. So there was a 10 to 15 year window of time where athletes could use EPO with a degree of confidence that no contemporary test would be able to definitively prove they did so.
The result was that many of the results of cycling's top races during the 1990s and 2000s had to be re-examined when it finally became clear that many of the contenders had been blood doping during that period (see http://en.wikipedia.org/wiki/Doping_at_the_Tour_de_France#Do... for examples from the Tour de France).
So the "hundreds of controls" defense is a bit weasel-wordy. It doesn't mean so much to pass hundreds of tests if those tests were given at a time when the testers didn't know how to catch the thing you're accused of doing.
It doesn't mean so much to for testing agencies to collect those samples when they themselves know they cannot test them. And then certify them to be clean.
Secondly the sheer count of its numbers in occasions, places, people, labs, qualification of testers all turning out to be false negatives over the years is impossible.