They can't have been heard, or the crowd do not know what to do when they hear the shout. Not one spectator took cover. I would not describe those shouts as particularly urgent ones, just like most on the tour these days. And no-one shouted again when it was obvious the ball was going into the...
There has become a trend in professional golf where shouting fore and therefore alerting people to possible danger seems to be less prevalent than it used to be. The reason being that if the ball hits the crowd, it stops it going into further trouble. If I were organising tournaments with lots...