Sastre did nothing before then because his wings were clipped after Fränk's escape to Hautacam worked and the team had the maillot jaune coming into the final set of mountains. He wanted to attack on the Jausiers stage, over Bonette, but asked Fränk and was turned down, so he rode like a good boy and stayed with the group that day, staking everything on the Alpe. The Schlecks have whined about it ever since, as if Fränk wasn't going to lose the lead to Evans in the time trial anyway. He was helped by the fact Evans had one of his traditional pre-2009 sulks when nobody would work with him (the only rider willing to help him chase Sastre was Kohl, who had flushed his final blood bag and was running on empty, and he had both Schleck brothers and Valverde running interference, he couldn't let Fränk go, he's the maillot jaune, and he couldn't let Andy go because if Andy got to Sastre they'd ride together).
And hey, if you tell him he won one of the worst Tours in 30 years, he should respond the same way Óscar Pereiro once did when told his victory was a fluke - I've got a yellow jersey at home, so I don't care.