THE MINER OPERATOR BACKED THE CONTINUOUS MINER OUT OF THE FACE IN PREPARATION TO ROCK DUST THE FACE WITH A BANTAM (MACHINE MOUNTED) ROCK DUSTER. THE VICTIM WAS IN THE PROCESS OF DUMPING A BAG OF ROCK DUST INTO THE HOPPER OF THE DUSTER; HE LOOKED INTO THE HOPPER AND NOTICED SEVERAL SMALL CHUNKS OF SHALE ROOF ROCK LODGED AROUND THE AUGER OF THE ROCK DUSTER. HE HOLLERED AT THE CONTINU