Pozidrive - The input lever is attached to the end of the control shaft (with the nut that did come undone) - then the shaft runs through the TR servo assembly with the piston section as an integral part of the shaft - the shaft then runs out the other side, through the TR drive tube, through the duplex bearing and is attached to the spider with the nut that didn't come undone.
A TR control input moves the input lever, but only enough to displace the pilot/spool valve in the servo - this directs the hyd fluid to move the piston (which is part of the control shaft) which moves the spider and changes the TR pitch.
The feedback/followup movement of the control shaft recentralises the spool/pilot valve in the servo, fluid stops being directed and the TR pitch stops changing.
The whole system is designed to have hydraulic assistance and that allows the autopilot to create inputs to the spool/pilot valve without the TR pedals needing to be moved.
I don't think the input lever has enough mechanical advantage/leverage to move the control shaft in a manual mode, even if you and the control runs were strong enough to move the pedals.