Your right, some type of cut off switch could work. However I know of this happening twice in 10 years on my lake. Both lifts had breakers and switches to stop it. Sometime they just fail, for we have 5 boat lifts, and have made them all so that you actually have to stand there and hold the switch. Also yes we had a close call, a guest lowered a seaddo lift jumped on and took off. The lift unwound all the way and started winding up in reverse. We caught it befor is caused any real damage, but was a close call.