Stage 3 was just the ups and downs of professional road racing. Thats the way it goes.
Stage 2 had almost EVERYONE crash on a decent that was predicted to be too dangerous beforehand. The motorcycle crashing and spilling oil was only one small part of it but probably the straw that broke the camels back. Everyone was SOO fed up with it that they went along with Cancelera. There are no hard and fast rules about it. The riders there at the time will make up their minds as it happens.
Anthony