Boomtown the FAC flight envelope functions are not the same as the fbw protections. I would argue that selecting the two FAC off will put the aircraft into alternate law in the same way that selecting two functioning ADR off will achieve the same result.
I may have missed it in this now huge thread but what were the symptoms the aircraft was displaying that the crew were trying to correct? Was it directly connected to a FAC or did the previous history of the FAC predispose them to think that was the cause?