My wife (pro per) recently settled a probate case in ADR and signed the paperwork, now one of the other attorneys wants us to sign another release.

Unfortunately, unless all of the parties agreed to have the ADR act as a final order of the court, under the probate rules (specifically Rule 29) exclude arbitration as being binding on all of the parties.  So yes, the guardian ad litem and fiduciary can take the case to trial if they so choose.  The two types of agreements, the hold-harmless and slander, are typical agreements that are utilized by guardians and conservators in probate court.  From the way your question was presented, it appears that the guardian and conservator are having you sign a separate agreement from the one agreed to at ADR, therefore it should not be a similar or same type of agreement as before. *The answer provided is for informational purposes only and does not create an attorney-client relationship between the question presenter and Laura B. Monte, Esq. or Donaldson Stewart, P.C.* *Laura B. Monte, Esq. is licensed only in the State of Arizona, therefore any answers presented are based solely on Arizona case law, laws, and rules.*