The separate note is essentially meaningless. Moreover, the former employee almost certainly does not understand the meaning of the word “duress.” Duress means that some physical violence or other illegal act (or threat to do those things) was used to force a person to act against his/her will. Putting a gun to the ex-employee’s head and telling him to sign the agreement is duress. Telling the employee he needs to sign the agreement in order to get the offered severance pay is not duress.