On November 27, 2002, about 1700 Pacific standard time, a Cessna 172N, N2423E, veered off the runway and nosed over during the landing rollout at Hollister Municipal Airport, Hollister, California. Wollard Aviation, Inc., d.b.a. Ahart Aviation Services, was operating the airplane under the provisions of 14 CFR Part 91. The certified flight instructor, the sole occupant, was not injured; the airplane sustained substantial damage. The local personal flight originated from Livermore Municipal Airport, Livermore, California, about 1615, with a planned destination of Hollister. Visual meteorological conditions prevailed, and a flight plan had not been filed. In a written statement, the pilot reported that while on the final approach for runway 31, she noted that the airport's windsock was indicating calm wind conditions. While on the landing roll, the pilot applied brake pressure. The airplane immediately began to veer to the left and the pilot input right brake pressure, in an effort to counteract the change in direction. Despite her attempts, the airplane continued veering to the left, off the runway surface. The airplane encountered a ditch and nosed over, coming to rest inverted. The airplane incurred damage to the wings and fuselage. A Federal Aviation Administration (FAA) inspector examined the airplane after the accident occurred. The pilot reported to the inspector that she thought the brakes may have malfunctioned during the landing rollout. The inspector stated that he completed a thorough examination of the wheel and brake assembly, and he found no anomalies or evidence of malfunction or failure prior to impact. The airplane was removed from the ditch and taxied to back to the operator's tie down area without mishap.