Well,
Stage 3 or 4 (cannot recall immediately) was right after a significant crash the day before. I think there was a feeling when a small group broke that they were all not going to challenge for anything, and the entire peleton kind of took the day off.
I am not convinced yet that the Peleton is clean until all test results come back (and even then I will not be completely convinced). However, I think there are some signs. Boonen broke on a relatively easy hill. I know he is not a climber, but I was even surprised at this. I just do not see him breaking on that hill in prior years. Any other opinions?