Regarding the fuel issue, has anybody considered that they didn't fill their tanks to the brim? Many riders are know to fill only what is necessary for the stage without taking into consideration a little extra in case of getting lost.
Remember Hélder last year (or 2011, can't remember) when he was leading the stage whilst everybody else got lost with navigation. He turned around thinking he was wrong, then went back the way he came from because he was correct. He had to stop because of a slight extra few KMs. I believe it was the Aussie Jacob Smith who gave him a few litres in his Camelbak to him!