According to the pilot of the tail-wheel equipped airplane, his pilot rated passenger performed a normal wheel landing. During the landing roll, the airplane drifted to the right but could not be corrected with left rudder input, so left brake was applied. The application of the left brake made both pilots brace themselves, and they inadvertently depressed both sets of brake pedals at the same time. The brakes locked and the airplane nosed over, resulting in substantial damage to the wings, fuselage, and vertical stabilizer. The pilot reported there were no mechanical anomalies with the airplane. The wind reported at the airport about the time of the accident was from 230 degrees at 4 knots.