Contributory Negligence
Contributory negligence is very often used as a defence in legal cases where one party tries to recover the cost of damages suffered as a result of an accident caused by the other party. This often comes into play in car accident cases irrespective of whether the parties have car insurance or not.
Very often in any type of accidental damage claim you will find that there was some degree of contributory negligence; in other words, both parties should accept some responsibility for the accident in a greater or lesser degree, depending on the level of negligence.
In car insurance two examples that could be used are negligent driving or driving without a seat belt. For example, I drove into your car from behind, I am guilty. But you did not wear a seat belt and therefore your injuries are worse than what it would have been had you wore your seat belt. I will accept my guilt but will claim contributory negligence on your part to try and reduce the amount of the claim I am (or my insurance company is) responsible for. Not wearing your seat belt, which is compulsory by law, has contributed to the extent of your injuries and you are also guilty to some extent.