I've towed lots of times, car trailers, caravans and motorbikes but even though I know my load is safe I become paranoid and sometimes I think I've been looking in my mirrors as much as looking ahead.
Reference trying to stop the driver, I think it's because of all the road rage that people are reluctant to stop no matter what you do. Years ago I was driving a lorry and behind a tractor towing a big trailer full of large hay bail, the round type. When I saw one dislodge when it hit a tree I spent the next mile trying to stop the driver to no avail.
Eventually the bail fell off, I expected it and drove round it and then saw a gap allowing me to pass the tractor and stop him. He hadn't even noticed and didn't really seem to care. Another couple of miles on I came to a police station where I reported the incident and the fact that the driver wouldn't stop.
The police didn't seem surprised but sent a cop out to direct traffic. A sign of the times I think.