CANNES, France –- All rumors about the prizes at Cannes are essentially worthless. Why don’t I know this? I could make up my own and do just about as well. It is apparently true that Sam Jackson told somebody there were going to be “big surprises” when the awards were announced, and there were; never before has a jury honored the casts of two films with ensemble acting awards, and certainly no one predicted that Ken Loach’s “The Wind That Shakes the Barley” would win the Palme d’Or. When it did, there was much agreement, and, yes, much surprise.