The flight instructor reported that during a flight review, the private pilot had completed 6 touch and go landings, in gusty wind conditions. During the subsequent approach, while the airplane was in the landing flare, a strong wind gust forced the airplane out of ground effect, and the instructor called for a go-around. The instructor reported during the go-around, the private pilot did not add full power, and he took the flight controls, however, as he did so, the airplane was already in an aerodynamic stall. Subsequently, the airplane descended, rolled to the left, and impacted the left side of the runway, where it continued into the grass and nosed over. The right wing and vertical stabilizer sustained substantial damage. The flight instructor reported that there were no mechanical malfunction or failures with the airplane that would have precluded normal operations.