The captain always monitors unusual control inputs by the copilot. Those inputs would have probably killed a standing flight attendant in the back who got up to take care of a passenger in distress right after takeoff. I do not think you could put enough rudder into an A300 to rip the engines off. The vertical stab must have done it. It probably was separating from the aircraft causing the gyroscopic forces on the engines to make them separate from the aircraft. Wake turbulence normally does not cause much yaw and is easily corrected by aileron. Has there ever been a wake turbulence upset causing extreme yaw? I have never encountered one.