Having been on these Helis open door. You have a belt cutter and the 4 point harness is clipped on to the aircraft much like for high building work, however at the start and end of the flight the ‘seat belt’ is required.
So it could be they were belted in AND harnessed at the time if they were about to land at the NYC heliport..
That said no bags were allowed on mine (lockered at the heliport) with FlyNyOn and cameras were tethered to the harness.
It seemed like it was survivable for all, although if they were just harnessed in it would have been a worse impact for the passengers than the lap belted pilot.. as there is a good bit of give ie potential for movement on impact with the water. So I see some are suggesting they might have been conscious and able to try and get out but there is a possibility they were not.
As for flight suits.. I doubt many would do the experience if they had to have full flight suits on and even then it would have complicated matters further as they are fairly restrictive. I’ve worn them on a UK Coast Guard photo shoot and also transiting between North Sea offshore platforms, they for sure do not make it easier to exit an aircraft, so the argument about water shock or water survival is mute if you make it even harder to exit. I’ve also done the survival training for offshore helicopter travel and even those who have done it before in warmish water, with suits on can panic when dunked and fail to get out of the aircraft.
I don’t think there are any easy solutions to stopping a repeat of this other than mandatory twin engines (if proved to be an engine fault) and a no bags policy (if proven to be that) to prevent it having to go into the water in the first place.
Why the floatation devices failed should be the biggest future focus once the causation of engine loss is found.