I do not think the Fuel Ctoff/Run switches are mechanically connected to fuel system valves but are electrically connected in a circuit that controls electrically operated valves. If so there is a possibility that the fuel system valves received a spurious signal to cutoff the fuel.
From what I have read and viewed in video discussions the conclusion by investigators that the actual Cutoff/ Run switches had been operated is based on data from the recovered Flight Recorder and Cockpit Voice Recorder. Did the investigators access the crash remains and actually see and record the position of the switches? Is the flight computer given access to the circuits and able to operate fuel flow valves under certain prescribed conditions?