ALLEGED INCIDENT WAS TO HAVE OCCURRED WHILE THIS EE WAS HELPING TO UNLOAD ROCKDUST BAGS FROM SUPPLY TRAILER. HE SAID HE SLIPPED ON A PIECE OF COAL AND STRUCK HIS LEG AGAINS SUPPLY CAR. CAUSE O F INJURY WAS AWARENESS. COMPLIANCE WITH RULES/REGS WAS NOT A FACTOR, MINER ATTITUDE WAS A FACTOR, MINING EQUIP/SYSTEMS COULD BE A FACTOR, SAFETY RELATED ITEMS NOT A FACTOR.