i don't think anyone is saying it's your fault or that you/they should change the catch - just that the insurance company see it that way - something has worn out or broken on the car, so it's not an insured risk. By the way yorky, for example, the cam timing belt on a car can snap, basically rendering the engine useless forever and you have no warning, it just goes. You wouldn't expect the insurance company to pay out for that Ok with the timing belt people do have them changed every so many miles but there is nothing stopping it snapping either before or after it's changed.