In this short essay
http://shawnrohrbach.com/read/
an author recounts his experience of interviewing relatively low-level cyclists who were also doping.
What this may mean is that probably no one in the Tour is clean and that that's probably been true for 25 years, at least. Probably more. It's widely acknowledged that Mercx was a cheater.
As has been noted, running is no better. Especially in the masters ranks these days. I haven't raced in years now, but my son ran a couple of road races this summer. At both there old dudes (50+) who looked like only slightly skinnier versions of Arnold Schwarzenegger. Anybody that age can easily get a doctor to prescribe testoterone or HGH. It's like the scene in Breaking Away. Everybody cheats....
That said, LA didn't win. And if I'm right that everyone in the Tour dopes, still, somewhere, there's somebody who's pedaling away every day, naturally, who would win a clean tour - even if, as has often been noted, it was done at 25km/hr rather than 50.