Are you saying that control column deflection was in fact an FDR parameter for the accident flight?
Column deflection is an input into the B767 DFDR (as well as control wheel and rudder pedal position).
There are two position transducers on the ends of the torque tube (which runs between the control columns) and, optionally, one force transducer (Ref AMM 31-31-08 and 31-31-19, 21-12-03). Also, reference Boeing Wiring Schematic 31-31-01 Page 101 Sheet 4 and Sheet 5.
Having said that, I cannot say that the DFDR records this data.