Maybe Alberto wasn't present at the front, because he told Roche to be there:
From Nicolas Roche diary:
I was sitting in seventh or eight position, alongside my team leader Alberto Contador when, sensing the danger, he turned to me and told me to close the gap. I did maybe a 40-second sprint before settling into a good tempo at the front of the peloton.
I knew the guys ahead weren't going to waste their energy riding 100m in front of the bunch to the finish, especially as it was only the third day of the Tour, and my presence on the front was probably enough for them to ease up a bit. It wasn't long before they were back in the fold.
Great insight in Saxo-Tinkoffs acting on stage 3:
http://www.independent.ie/sport/oth...ize-yellow-in-adopted-home-town-29387517.html