The flight instructor and student were conducting an instructional flight in the tailwheel airplane when it veered left shortly after a three-point landing. The flight instructor applied right rudder pedal input and kept the elevator control full aft, but the airplane continued to swerve left. The flight instructor was able to regain directional control after he applied right brake, but the airplane then slowly nosed over on the runway. The upper portion of the vertical stabilizer and rudder were substantially damaged when they struck the runway. The flight instructor reported that there were no preimpact mechanical malfunctions or failures that would have precluded normal operations. The student pilot was uncertain if he removed his feet from his rudder pedals and toe brakes after the flight instructor took control of the airplane. Based on the available information, it is likely that an excessive use of wheel brakes was used to regain directional control which resulted in the airplane nosing over.