There is an observation in one of the videos.
We can see that before impact, the floats are deployed already. Reading through an amount of checklists, unfortunately I don't have a AS350 POH handy, the B206 states that the floats may not be activated in flight with speed above 54 knots. Autorotation speed of the B206L3 with extender is 65 Knots.
Anyone has a clue what the specs for the AS350B2 is?