Interesting. No apparent control failure but a loss of tail rotor effectiveness.
There's some debate as to whether a fenestron is a tail rotor. Notwithstanding that, there have been a number of cases where something similar has happened on Gazelles. IIRC, there was more wind involved with those (TBC).
Kudos to the designers, 20g and the cabin remained intact is great news.
Wishing a speedy recovery to the 2.
HD