Its a damn shame all around. It is a situation that could have only happened on a Sunday in one of the final groups. Had this happened on a Thursday there likely wouldn't have been fans in the bunker and he would have obviously noted that he was in a trap. I was very [censored]ed at the PGA until I heard that this note was handed to every player on the first tee every day of the competition.
1. All areas of the course that were designed and built as sand bunkers will be played as bunkers (hazards), whether or not they have been raked. This will mean that many bunkers positioned outside of the ropes, as well as some areas of bunkers inside the ropes, close to the rope line, will likely include numerous footprints, heel prints and tire tracks during the play of the Championship. Such irregularities of surface are a part of the game and no free relief will be available from these conditions. All bunkers inside the ropes will be raked each morning prior to play as normal.
2. The local rule allowing players to move stones in bunkers will be in effect.
While I don't agree with it (I think if the crowd is standing in it, it should be a waste bunker, thus grounding your club is allowable), it is pretty obvious that DJ screwed up. The only one who could have prevented it and really dropped the ball IMO here was the walking referee. He should have been walking up there with DJ making sure everything going on was by the rules. He is there to be an asset to the players, not a liability. That was on display when Bubba hit into the creek during the playoff and his ref offered the option of going to the other side of the creek to get a better angle.