The student pilot reported that, during a check ride, during a short field landing in gusting crosswind conditions, the touchdown was normal, but the airplane quickly veered to the right. He added that, he and the designated pilot examiner applied left rudder to no avail. The airplane exited the runway to the right, the right main landing gear struck a taxiway sign, and the airplane came to rest in the grass adjacent to the taxiway. The airplane sustained substantial damage to the right horizontal stabilizer. The Federal Aviation Administration inspector conducted a postaccident examination. He reported that the rudder system appeared normal and functioned properly. He added that there were no pre-existing mechanical conditions that could have caused the accident. The automated weather observation station located on the airport reported that, about the time of the accident, the wind was from 50° at 11 knots, gusting to 21 knots. The airplane landed on runway 33. The airplane information manual stated that the maximum demonstrated crosswind is 15 knots.