Whatever caused the tail to separate would have been felt by the pilot as a TR failure and we would all at that stage dump the lever - any cyclic input would likely be to try to keep speed (he won't have known the tail boom was completely gone) but he would have had zero directional control.
You can't simulate this type of failure and any control inputs the pilot made would have been fruitless.
What cause the separation of the MR and what looks like the top of the MRGB from the fuselage? Who knows, but in that condition the stresses must have been very high and any weaknesses in the transmission system would have been pushed to breaking point.
From the point of tail boom separation the chances of a good outcome are vanishingly small.
RIP.