The pilot reported that while being towed behind a tow airplane for takeoff, there was a slight drop of the right wing. The pilot corrected with aileron control to level the wings and at this point, the left wing may have come in contact with the grass on the runway, which provided enough drag to turn the glider 180 degrees to the left. During the turn, the safety link released. The glider then rolled backwards before coming to rest. Postaccident examination of the left wing revealed that the left aileron was substantially damaged and had separated from its mounts in the wing. The pilot reported no preimpact mechanical failures or malfunctions with the glider that would have precluded normal operation.