Nick, h'fire, whups - I guess you missed the part where I agree. As an instructor operating under the auspicies of the FAA, I am forced to reconcile the party line with reality (the party line being the RFH, and AC). BTW, the AC eliminates mechanical issues as a cause of LTE.
Anyway, as to what I think and teach as far as LTE versus all the other reasons a helicopter might go 'round on you - my (personal) definition of LTE is when the main rotor is creating more torque than the tail rotor can counter (at full pedal). All the other stuff (weathercock, vortex, MR vortex) are ways to experience unanticipated yaw, but not LTE.
Nick, I'm not trying to debate your point that letting RPM droop is a pilot error, and I agree that if you keep RPM up, there are very few helicopters that will experience LTE. However, once the pilot MAKES that error, you may reach the point where the tail rotor cannot overcome the torque of the main rotor. You yaw, and no application of pedal can stop it. Physically, aerodynamically and result-wise, the only difference between (shall we call it B206 LTE?) and low-RPM LTE is how you arrived. Important difference to be sure.
Anyway, I think the frustrations lie with having to toe the FAA line while trying to teach new students what's really going on. If I tell a pre-private student "there is no LTE except in a Jet Ranger", they aren't going to have a good time defending that statement with a DPE holding a copy of the Rotorcraft Flying Handbook or the AC. Better to have them understand the principles and mislabel them as LTE.