Wiggins 38x32
That explains a bit. So maybe a bit of a mistake on gear selection back at the office. Wiggins was clearly struggling on the steeper stuff.
On the other hand Cobbo (on 34x32) did look comparatively relaxed and fresh (on other forums it seems some are convinced he had some cow in his bidons on that basis alone) but there was a big difference in gearing so I guess that might explain it.