If the catalytic converter is rusted out, and it's required to be in good working order in order for the vehicle to be leased out, then the owner of the vehicle is responsible for fixing it.

The fact that it took an incident of some type to uncover the state of the converter does not make it the responsibility of the driver.

It is the responsibility of the owner to fix it and fight it with the insurance company to decide whether it is covered by the accident or not.

I agree with charles chambers, that, just because it took the accident to find out, it is not the drivers fault.

If you want to be an enterprenuer, there are some responsibilities that come with it. if you can not take the heat, well, you should be in business.