EE WAS WORKING UNDER THE FLOOR PLATE OF A D11 DOZER, BREAKING A FITTING LOOSE ON THE HYDRAULIC CONTROL VALVE. WHEN THE FITTING BROKE LOOSE, HIS HEAD HIT A CLIP HOLDING AN ELECTRICAL CONNECTION , CUTTING THE BACK OF HIS HEAD. HE WENT TO THE ER ABD 3 STAPLES WERE USED TO CLOSE THE LACERATION. THE COMPANY WAS NOT AWARE THAT THE EMPLOYEE RECEIVED STAPLES UNTIL 3/5/01.