After completion of BOP flushing, Driller and Floor hands broke out 5” pup joint. Driller lowered and tilted the elevator to unlatch pup joint. At the time driller lowered pup joint on Rig floor, Trainee Assistant Driller unlatched the elevator causing the pup joint to tilt on wear pushing and then bounced to floor man right foot resulting in a fracture of the right big toe.