Because the commercial third party liability insurance lists "the personal injury or death of the insured and his family members, the loss of all or entrusted property, the personal injury or death of the insured motor vehicle driver and his family members, and the loss of all or entrusted property" as the scope of non-compensation.
Article 5 of the model auto insurance contract in the Basic Provisions of Commercial Insurance for Motor Vehicles of China Insurance Regulatory Commission stipulates that the insured motor vehicle causes the following personal injuries or property losses, regardless of whether the insured shall be liable for compensation in law:
(1) Personal injury or death of the insured and his family members, and loss of all or entrusted property;
(2) Personal injury or death of the insured motor vehicle driver and his family members, and loss of all or entrusted property;
(3) Personal injury or property loss of other personnel on the insured motor vehicle.
What needs special attention is that the standard of dividing family members in insurance is to look at "economic independence" rather than blood relationship. Those who are not financially independent are regarded as family members, and those who are separated and financially independent are regarded as third parties. If they are brothers and sisters, they are not regarded as a third party before separation and cannot enjoy the protection of the third party liability clause; But once you leave your family and become an independent economic subject, you will be a third party in the full sense.