If both sticks had been linked then the force pushing one forward would be translated into the other stick. In this case having seperate sticks meant that the other pilot only had only to press the disconnect button and command a pitch up with his working stick. I have read the report and I don't believe that he did this , but instead merely commanded full back stick instead to counter the pitch down.. For this reason I question the quality of the training received by the crew.
If the sidestick is pushed with enough force, the AP will disconnect. this is what happened in this case. The CM1 assumed the AP was still engaged because he couldn't move the stick. The CM2 by pulling back did the right thing as the sum of the two sticks is combined and this would have cancelled out the forward movement of the CM1's stick.
Had the aircraft captain, a military officer with all the associated military ethos associated with such a profession, confessed ALOT earlier as to the circumstances then all this baggage of cultural, endemic behaviour across the AT/AAR fleet been avoided.
I get the impression he didn't understand what had happened until a long time after the event.