SUPERVISING THE INSTALLATION OF ROOF BOLTS WAS HELPING TO GUIDE A GOPHER BOLTER ONTO A ROOF BOLT.THE GOPHER BOLTER SLIPPED OFF THE HEAD OF THE BOLT, THE SUPERVISOR LOST HIS BALANCE AND FELL FO RWARD INTO THE ROOF BOLT AND PLAT THAT WAS BEING INSTALLED, CAUSING A LACERATION ON HIS RIGHT CHIN AND AN ABRASION TO THE RIGHT SIDE OF HIS HEAD.