HF, I hate to argue but my concern is in your wording. The sentence that I re-quoted states that a tail rotor drive shaft failure involves a loss of tail rotor pitch control, obviously it doesn't.
We descend toward semantics here (and off thread topic a bit too), however I will attempt to clean it up for you ST, though I feel you are reading differently from the intent. Does this help ?:
Loss of tail rotor control: You are not able to affect yaw control using the yaw control pedals - it is a true emergency. This could be a stuck control (left pedal, right pedal, or centre) OR it can be a total loss of thrust (broken drive shaft or gear box) in which case the pedals move but the aircraft does not react in yaw to the input. It can occur on any conventional helo, but is relatively rare. Part of the training on every helo.
The Puma incident may need a little more info to explain it to us non Puma types. What is the consequence of the "tail rotor pitch control spider failure" and why did they ditch?