THE EE WAS INSTALLING A ROOF BOLT TO SUPPORT A BROW. HE STARTED THE HOLE W/A SHORT STARTER STEEL, BUT DID NOT DRILL THE HOLE STRAIGHT. WHEN HE SWITCHED TO HIS REG. STEEL, THE BOTTOM OF THE ST EEL WAS NOT PLACED PROPERLY IN THE CHUCK. THE STEEL WAS ON A BIND & WHEN HE RELEASED PRESSURE, THE DRILL STEEL SPRUNG BACK & STRUCK HIS RT.HAND.