Some sources do speak of some sort of "wire" (pin) involved in the (presumed) lock-due-to-malfunction of the TR by the technician.
Most sources now speak of right TR not operative for the past 3 days, maintenance delayed (by MEL), and LEFT TR found deployed (assumed to be commanded when trying to stop the plane).
The sources speaking of the slow speed/long time to take off are: ground witnesses, airport video recording, ground radar. Video recording shows the plane finally leaving the ground close to the end of the strip, close to the portion of the paviment that changes color (which somewhere it's said to be 600m long of aditional paviment). This is estimated to be some 500m longer than usual for this flight.