Dozy
Right, but the rudder position appears to be more-or-less centred correctly. Would the Yaw Damper not compensate? Unfortunately the graphs are imported at a low resolution, so it's harder to determine exactly what the Yaw Damper and TLU were doing exactly (0.5 degrees offset being relatively minor on those graphs).
I agree it is very difficult to read the rudder deflection - after a couple of attempts at digitisation I conclude the actual rudder and trim deflection are both around 0.3 deg rather than 0.5.
The yaw damper reacts to rate of yaw which would be VERY low in the early stages of a spiral divergence so it would be unlikely to have any measurable effect on these few seconds after AP disconnect. Prior to that of course the AP was holding the aircraft steady.