DURING A COMMERCIAL PLT CHECK RIDE, THE CHECK AIRMAN REDUCED THE THROTTLE TO IDLE TO SIMULATE AN ENG FAILURE. THE APPLICANT ENTERED AN AUTOROTATIVE LANDING & WAS ADVISED THAT THE MANEUVER WOULD BE COMPLETED TO A 3-FOOT HOVER. AT 6 FT AGL, THE APPLICANT DID NOT PULL COLLECTIVE PITCH NOR APPLY POWER. THE CFI TOOK CONTROL & APPLIED COLLECTIVE PITCH & POWER BUT THE DESCENT CONTINUED & THE HELICOPTER TOUCHED DOWN, BOUNCED, WAS RECOVERED TO A HOVER, & LANDED WITH NO FURTHER INCIDENT.