Something i did notice was that the greens, while firm, were giving up a lot of spin on approach shots. So the higher the shot that comes in the more the ball is going to drop and spin...a lot.
So it could have been possible that they were hitting irons a bit lower into the green to have more of the "hop and stop" action.
Lastly, if the shots you are talking about were coming from the rough, it's because it was so thick you couldn't spin the ball a lot and thus you wouldn't get a very high ballflight out of it either.