MANITOWOC 300 VICON CRANE SET SECTION OF SHORING ON TOP OF ANOTHER SECTION MAKING IT 2 FRAMES HIGH, SCAFFOLD WAS PINNED TOGETHER AND STRAPS DROPPED TO OUTSIDE OF SHORING AFTER BEING UNHOOKED O N FEEDER END. COWORKER THEN SIGNALLED THE CRANE OPERATOR TO HOIST UP THE STRAPS. WHEN THE OPER. PULLED UP THE HOISTLINE LEVER, THE BOOM RAISED TOO, CAUSING THE STRAPS TO SWING CATCHING THE LE