Yes, one time. The horse got all wild on me, as well as other horses in the group. I calmly jumped off. The instructors yelled at me to stay on. I wasn't having any of that. My choice was justified after one of the other people who choose to brave another horse going wild had to deal with hanging on for dear life as the horse was sprinting at full speed. The person eventually bailed, and all was well. No injuries for any person or horses.