This is really interesting:
Fretta’s four-year period of ineligibility began on June 11, 2012, the date he accepted a provisional suspension. As a result of the violation, Fretta has been disqualified from all competitive results achieved on and subsequent to August 18, 2010, the date USADA collected the first blood sample that was included in Fretta’s individual longitudinal blood profile.
He is suspended for four years, but he has an additional two years lost because of samples contributing to the conclusion of doping. So in effect he is getting six years, retrospective plus prospective. If I understand this passage correctly--and maybe I don't--they are not sanctioning him just from the date of collection of a sample that is significantly different from the baseline, but from the date of collection of samples that were used to construct the baseline? Doesn't make sense.
Either that, or the 2010 sample was suspicious, but not considered significant until other samples were collected later. Either way, I never heard of this being done in cycling. Imagine if in the Contador case a review of blood data led to the conclusion that several samples, taken together, indicated doping. And the sanction began with the collection of the first sample. He could have lost not simply his 2010 TDF and 2011 Giro, but also his 2009 TDF. There would have a huge outcry over this, needless to say.