Similar story: I once towed a jet ski from salt lake to lake Powell with the trailer resting on top of the ball and not actually secured to the ball. It somehow didn’t bounce off along the way. We hooked up really late the night before in the dark and somehow must have screwed it up. Figured it out a week later when we were pulling the jet skis off the lake. A couple hours after we fixed it I had to make a true emergency swerve to miss a family of deer on the road. I can’t imagine the carnage that the trailer coming off would have caused in that situation.