Servo Movement
Point is valid Eric, but there is another factor, or should I mention two factors in play. The breakout force required to move the pilot valve, and the stiction of the system left after rod disconnect. If high enough, the valve could remain centered.
All this should come out in the detailed investigation, and you may be correct. As I wrote, though, if a servo went hardover ( and BTW, my recollection is anything but 100% accurate ) the servo's are typically designed for 100%/second rate, and if the servo went to full extension at that rate, the resulting initial maneuver would have been different than reported.
John