Arnout said:
If that was the case, there would be two options.
A. He doesn't attack because he doesn't care about a few seconds anyway, probably only will attack much later for bonus seconds.
B. He would have attacked and gained a much bigger margin.
These mere four seconds in 1100 meters tell you that he couldn't go any faster. Remember he stopped pedaling before the line, that's usually a sign of a rider who is very tired.
you could be right. but, when he suffers, he can't hide it on his face (see tourmalet) and the difference between him and everyone else was just huge in the last days (not big, huge!).
to me, what I saw, is that he understood that it was too late for catching anton when he attacked, so he stopped, but when he saw nibali on the red zone, he went again, without any sign of trouble. before attacking, probably he told nibali that gaining time on scarponi and catch anton was not his (contador's) problem, so he let nibali with zero left for the final meters and maybe, tomorrow's stage, and, before that, he said the same to scarponi. still gaining time on him, scarponi and the others. now anton is "the" problem, so he better enjoy this win.
the way he ended, in the "zoncolan", that was "i'm the boss no matter what happens and, i will be there andy. just wait."