I would believe half of what the weight police say on here if they backed up their statements with facts. That outback story was sad but it didn't really prove anything. We have no idea if that truck even had a brake controller nor did the article say any laws were actually broken. Accidents happen all the time but if you are not braking any laws it's hard to prove negligence.
I'm all for being safe but there are no laws that I'm aware of in a non commercial setting that regulates staying within manafacturers tow ratings.
As far as the op is concerned I would imagine that either under weight or over weight the insurance will always try and deny the claim but will eventually have to pay. What they do after that is up to them. Even if you were totally legal your rates would still increase or possibly be dropped.
I would just like one example nationwide where a person was proven negligent with his claim denied and jail time was given over a overweight recreational wreck. Ive never seen one. I hear second hand claims and off the wall stories but nothing proven.