resp to Kevin
"If the system was getting two sets of information that were at odds with each other, then disconnecting autopilot _might_ be a sensible thing to do. You know _something_ is wrong but not _what_ is wrong."
No, the safest thing to do would be to do nothing, to simply have ignored the input and carry on just as before.
Why? Think about it. The auto-pilot was engaged and the aircraft was in a safe situation, probably flying straight and level. Errant input appears, ignore the new inputs, you know something is wrong, but not what, sound an alarm to get the attention of the pilot, issue a voice warning to state the problem and suggest disengaging the auto-pilot.
If the system disengages the auto-pilot automatically, the flight control system will read the demand inputs from the flight controls, stick, throttle lever, which can be in any position, the flight control system will regard these inputs as being genunine inputs from the pilot, which they are not.
I would argue it is safer not to disengage the autopilot, having said that, if the state of the aircraft when the autopilot was engaged was losing height and then the errant input from the AIDRS occurred, you might decide that leaving the auto-pilot engaged might be an unsafe situation ( depends how high you are and how high the mountains are!), but you're still at risk of the flight controls being in a non-suitable state and the flight control system taking those inputs and moving the control surfaces to achieve what it thinks is demanded input by the pilot.