The only way I see Lance in Yellow is if something happens to Contador, such as a crash.
Lance, whatever else you may think of him, is too much the team guy to attack on a regular stage.
I think that he could have continued on yesterday after making up the 30+ second gap to the yellow jersey group on that last climb, but he stayed with his teammate.
During tomorrow's time trial, who knows what may happen. i don't see him holding back anything. If he's that much stronger/ faster, so be it.