I don't see what was particularly suspicious about it, compared to any other performance by one of the top guys. He gapped Purito and Valverde, who didn't try to follow him at first, by some 15 seconds on the climb where he attacked (actually, he gained most of that advantage early on, and it remained stable for the rest of the climb). The gap was slowly built up when it was basically Paulinho and Contador vs Losada. By the time Contador and Tiralongo went on their own, they had slightly over a minute. Then it was Contador and Tiralongo vs Losada, who had been in the break, and they put another minute on him and Purito's group. In the final climb, Contador lost 2 minutes to Valverde, helped by Quintana and Intxausti for some kilometers, and put what, another 15-30 seconds on a clearly defeated Purito? Not to mention some people who were in Contador's group when he went with Tiralongo, like Henao, never lost that much time and followed Valverde to the finish line.
Is Contador doping right now? Probably, yeah. But yesterday, it all came down to a tactical move. No particularly outstanding performance from a purely physical point of view.