An interesting twist in the Landis confession

BikeMonkey Guest PostESPN is reporting that Floyd Landis, previously a world-level professional cyclist, is now admitting to using performance-enhancing drugs for “most of his career”.
You will perhaps recall that the Landis case has appeared on the DM blog a time or two before.

In a brief fan’s overview for those too lazy to Google, steadily improving journeyman* / domestique Floyd Landis started to show some real prospects as a Big Tour winner with some big performances as a super-domestique in 2004, and an initial foray as team captain in 2005. Landis was showing excellent signs of class in the early 2006 Tour but the usual Tour deal-breaker of a few great performances from competitors and one bad day had Floyd on the ropes. Stage 17 saw Floyd come out and just slay the competition with an all day break to put himself back in the race he would eventually win. It was a great stage to watch. A desperate attack in the early going which was surely doomed to failure. (This is a common rhythm for the bigger bike race stages- one man is usually unable to hold off the peloton until the finish if the teams are determined to catch him.) Yet Landis did. Despite the fact that the main General Classification teams knew he was riding back into and possibly away with the entire race. They couldn’t catch him. Floyd just kept hammering away the kilometers, obviously suffering like a dog and continuing to pour on the power. It was amazing.

He tested positive for testosterone doping in samples collected after that fateful race day. Given that this is a substance to be found in humans anyway, the conviction hinged on analysis of the ratio of carbon isotopes in the detectable testosterone. This ratio analysis indicated the presence of exogenous testosterone- i.e., that not manufactured naturally by Landis’ body.
Allegedly, anyway. Landis fought tooth and nail to overturn the conviction. The reporting from ESPN gives us a little clue as to why a now-admitted long-term doper would have fought so hard in that particular conviction.
He didn’t do it.

HAHAHAHA! Okay, reel yourself back up off the floor and consider this claim from Landis, as reported by ESPN.

As for his own positive test, Landis still maintains that result was inaccurate and that he had not used synthetic testosterone during the 2006 season — although he now admits he used human growth hormone during that time. At this point, he said he does not want to dwell on any of the issues he and his lawyers hammered at during his case.
“There must be some other explanation, whether it was done wrong or I don’t know what,” he said. “You can try to write it however you want — the problem I have with even bothering to argue it is [that] I have used testosterone in the past and I have used it in other Tours, and it’s going to sound kind of foolish to say I didn’t.”

And this is what makes me nervous as a scientist-fan with an unhealthy interest in Teh Dopingz.
There appears, from the outside, to be a lot of voo-doo going on with these doping criteria that hinge on population statistics and what are, at root, very limited numbers of studies. Of course, the doping authorities probably (I hope) have access to a lot of well validated, blinded data from all of the routine drug testing during sport. Although when a case gets dragged into court, it sure doesn’t seem like they do. Okay, I admit I’m highly suspicious about the assays and criteria.
In a case like this…who knows? Landis has a Viking armory of axes to grind. Part of his confession is devoted to naming names. Including the most famous of homeboys from his era who are still on the road- Zabriskie, Leipheimer and, of course, Lance Armstrong. This agenda tempers my ability to believe in the “He’s confessing, why would he lie about this specific detail” theory. But still…It does raise a flag.
I’m left with three hypotheses, assuming Landis is not lying about Stage 17.
1) Someone else added synthetic testosterone to whatever brew Landis was taking and didn’t tell him.
2) HGH (and or whatever else he was taking) has effects which alter the testosterone carbon isotopes in a way that mimics exogenous doping. This one is amenable to testing so I hope the doping scientists get on this.
3) Someone in the analysis chain put a finger on the scale to find false evidence of doping. I really, really, really hope this wasn’t it.