have you looked at the details of stage 10? That's the day to try to effect GC, not today's stage. At just 156km, the second half with the climb of Tourmalet is the place to start sending attacks to shake up GC. With the downhill finish today, no GC threat was going to stay away. The most vulnerable person tomorrow will be Evans, who will have to cover the attacks without a lot of team support.
It could be a good day for Pereiro, who has been riding strong. The team could send him out on Tourmalet and he could see it as a day to be an overall podium contender.