The A310 has the same overly sensitive rudder limiter system that the A300-600 has. Since this failure occurred 30 minutes into the flight, the aircraft should have been at cruise speed when this happened, thus the rudder limiter would have been fully activated (i.e. in the configuration creating the highest sensitivity).
It will be interesting to see what "control problem" was encountered that initiated this event.
I would also imagine that this aircraft cannot possibly be put back into service without the vertical fin being thoroughly inspected (including all 6 attactment lugs).