How did Lance Armstrong pass his drug tests?
This is my understanding of the situation
EPO was developed as a drug to treat very ill people. It was not detectable in tests and had clear benefits for cyclists. It first surfaced in the media as a cyclists started dying in the night. It turned out they had very high red blood cell counts. It was assumed that they were taking EPO
So the sport had 2 problems. Cheating with a drug they couldn't detect. Athletes dieing in the process
A pragmatic approach was taken. A cap was put on red blood cell limits. If you went over it was just a 2 week ban until things returned to normal
This I think reduced or eliminated the deaths but was seen by many as a nessage that EPO is OK if you stay within the limits
Thats from my memory of the media at the time. Please point out the effors
Witness have come forward to say Lance Doped and we have the B sample scandal.
Again from memory. In order to validate new EPO tests labs were allowed to test old tour urine B samples. Lots of these were found to contain EPO. Some one then did some clever digging and showed that some these anonymous samples came from Lance Armstrong
No idea exactly how true the b sample bit is
But in summary Armstrong's critics claim
He passed the first time as EPO couldn't be detected
When they checked the B samples with newer technology he failed