From the video it does look like a tail rotor failure. I've only seen one video and it's difficult to tell if there is a tail rotor attached to the aircraft. Maybe someone has seen some better footage.
I had a tail rotor failure in '93 in a Hughes/Schweizer 300. The locking nut from the transmission output shaft connecting the TR drive shaft came undone. For a split second you're thinking "this has to be something else". I continued with my autorotation and thankfully landed upright. I did spread the skids though - she sat a little closer to the ground after that.
