Settling with power is the US term for Vortex Ring.
I don't think so...
Errr yes it is the US term for Vortex Ring.
Settling with power - Wikipedia, the free encyclopedia
I'm not saying that is what caused this but my statement is fact.... but the aircraft clearly had enough power to hover looking at the departure. If the aircraft had power applied and the RoD was not reducing then it could well be VRS but that is only speculation.