Employers are responsible for making additional payments to injured workers in all cases EXCEPT:

In the context of workers' compensation, employers generally have certain responsibilities when an employee is injured on the job. However, there are specific circumstances under which they are not required to make additional payments to injured workers.

The scenario described in the correct answer highlights that if the injury was caused by a third party, the responsibility may lie with that third party rather than the employer. For instance, if an employee is injured due to faulty equipment manufactured by a different company, the injured worker may pursue a claim against that third party while still receiving workers' compensation benefits.

This is distinct from instances where the employer has contributed to the injury or where the employee's own negligence led to the injury. In these cases, the employer could still be held liable or the employee’s own conduct might influence compensation claims. Furthermore, workers' compensation is designed to provide benefits regardless of fault, ensuring that employees receive necessary medical care and wage replacement while not allowing them to pursue additional claims against their employer for the same injury in most cases.

In summary, the correct answer reflects the specific situation where employers are not required to make additional payments because the issue lies outside their direct responsibility due to the involvement of a third party.