Had a few scares in my days.
First was from too little tow vehicle. We started out towing an 18 ft travel trailer with a Ford Sport Trac. All the numbers met the book but it would sway and start wagging the dog. This was using the old friction brake style sway control. BTW Ford later amended our owners manual to lower the tow ratings.
Coming up out of Florida had a dust devil hit our fiver broad side saw it coming across a farm field but couldn't avoid it. Pushed the 5er sideways enough to grab the shoulder.
Surprisingly I didn't loose control when a pickup hit us on the rear side while trying to pass. In fact for a second I didn't realize I had been hit.