NERA and the LRC are separate entities, so even though an agreement was reached to the satisfaction of the NERA, there is nothing preventing the employee taking it to the LRC. That's the important point here, it's not a state agency chasing you with the LRC, it's the employee seeking further redress.
A similar, though not perfect, analogy would be satisfying the Health and Safety Authority with certain actions, but an employee still pursuing a claim with the injuries board for an injury (I said it wasn't perfect). Separate identities and in the latter case, it is the right of the employee to pursue this.
The LRC may look favourably, though, give the fact that you satisfied NERA with your actions.