Auto Insurance Claims: auto accident liability coverage, car thief, truck liability

Question
From Georgia - my sister had a truck; liability coverage; her son not living with her at time of purchase, but came back from rehab later. She did not put him on insurance as driver. He has previous DUIs but had valid driver's license at this time. He took truck while she was at work (11-7 night shift at nursing home.) While drunk, he ran off road into a cemetary causing damage; totaled truck. First contact with insurance adjuster who says they will not pay for truck nor damage to cemetary because he was not listed as driver. He is "excluded." Is this true? Are they not required to pay for anything?

Answer
He would only be "excluded" if she specifically listed him on the policy application as an excluded driver and given his prior record, she likely did.

If he took the truck without her permission then no liability coverage would apply. Liability insurance covers the covered drivers and owner, not the actions of a car thief.

If she had purchased comprehensive coverage then the loss could be covered as a theft, but only the damage to the vehicle.  

The insurance company is only required to cover the risk that they are being paid to cover.