When Contador was patting Schleck on the back on Ventoux, it was to tell him that Contador was not going to pull through and for Schleck to go right ahead.
Implicitly or explicitly, there was also the understanding that Contador wouldn't pull through, but also wouldn't attack at the line.
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You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.