LTE is simply a term used to describe the condition of flight that occurs when one applies more torque to the main rotor than the tail rotor is capable of counteracting. I have personally had LTE in two types or AC, the B206 and R44.It isn't some mysterious condition that occurs out of the blue and if its recognized early enough and with sufficient altitude it is easily overcome. But it is just another term same as vortex ring, and you don't hear anybody arguing about what that's called.
In the video the guy lifted off and started yawing to the right pretty much right away(my guess is he had the left pedal to the stop), As he gained a little altitude( and pulled more power)( left pedal still to the stop) the yaw rate increased, Then at one point the AC seemed to transition to a very slow forward flight and stop yawing for a short time. The AC then seemed to pitch up loose apparent airspeed and then start yawing again (spinning now) losing RRPM ( by the sound of it) until it hit the water. A rough ratio for modern helicopter Main to tail rotor RPM ratio would be 7:1, so as the main rotor lost RPM the tail rotor lost 7 times as much, and became that much more inefficient, causing the increasing rate of yaw and the sh!ty ending.
From my experience and my opinion, the corrective action cold have only been reduce collective(reducing Tq) and regain RRPM and even beep it up if possible and get some airspeed. Of course this is all assuming that there was no mechanical failure.
just my opinion