Nobody is saying anyone should have "stopped".
All those riders you mentioned continued at a normal pace up the mountain.
Contador attacked with all his might in order to take as much advantage of the mechanical as possible.
There is a big, big difference. Hopefully you can see that.
As for Menchov and Sanchez, they would not have attacked if Contador hadn't, but once he went they had no choice but to follow.
The difference I see is that Andy CAUSED his mechanical issue while HE was attacking them. They were covering his move. Then Andy screws up. Now everyone is supposed to stop and wait for Andy to catch up, AGAIN! Thank god Cancellara wasn't up ahead or he would have shut down the stage AGAIN. Or course, the Saxo boys didn't have a problem when everyone was stuck behind Frank Schleck's crash. They put the hammer down. That's the only reason Andy is in the position he's in.