I do apologise most profusely, this reference people are making to a video? I've only just found the link by scrolling thru from the beginning again! Ooops.
As Ascend Charlie states, this is most definitely loss of directional control due to the major gusts he was obviously experiencing. The gusts must have robbed him of most of his coanda effect thus making directional control more sensitive and he moves into pilot induced oscilating in yaw and then the nose dips.
Quite frankly, he must be one of the luckiest guys on the planet - if she had rolled to port instead of the way she did go, he'd have fallen a n enormous distance to his untimely end.
Correct - NOTAR's don't suffer from LTE (no helos do except OH-58's and some 206's but there is an argument for them losing LTA during certain cross wind/tail wind situations and at the bottom of auto's (even though the TR is in the cone, it's still a tail rotor design but not situated at the end of the tail cone but at the beginning..
Ascend - when did you retire. You must have gone well past 40 yrs of flying?