As long as it was covered by insurance initially if there are any other problems found after they approved the work they usually have to fix it. My brothers Tiburon was close to being totalled, after they started repairing it they found out it needed much more. The insurance company had no choice but to eat it, and the additional work would definitely have totalled it if they caught it before. If the shop did poor work, I'm sure the insurance company would want to know and they may be able to help him out. Body shops have to have a good relationship with the insurance companies that deal with them or they can lose a lot of business.