hmmmm....
Actually why are we focusing on the tail rotor when after all the 5 main rotorblades aren't there, surely that's the cause ?
(the above posted in 'jest' to show that uninformed spceculation is just that)
SAS, it doesnt necessarily follow that the tail rotor would be that damaged, if the aircraft rolled to the right and the MRB hit the water first the tail rotor would be stopped or moving slowly by the time it hit the water (speculation again)
The RTS covers all aspects of the aircraft operation and maintenance, anything arising from a design change or mod is approved (or at least checked)by the EA, especially if it imposes a maintenance burden. Manufacturers don't actually have the authority to unilaterally apply actions to any aircraft without MoD approval (in the UK at least).
Knowing the construction of the 101 in detail I would hypothesis that the amount of nose damage seen in the pics was caused by the recovery team, the 'failure' point is at the main lift frame (ie the strongest bit of the aircraft) not at a module joint, as always until we all know all the facts we know nothing
As an aside I am sure that if it had been a TR problem we would have heard about it by now!!! (you couldnt keep that news quiet and there are parties around that would spread news like that everywhere)
DM