The guy in the tower is waving a GREEN flag...
at the start (8s) double yellows are being waved...once Sutil’s car is on the crane and the crane is moving out of the way (1m) the green comes out- that’s the way it should be...Bianchi’s accident occurs 10 sec later (1.10)
a yellow does not enforce a certain speed limit; it means you have to drive slower in the yellow area this time around versus last lap...i dare say double yellow or green would not have made a difference...