Sad that such a tragic incident can lead to such an interesting thread.
In any case, I find the whole "Nato Strop" arugment slightly bemusing. Members of the Mountain Rescue Teams are highly skilled individuals, but more over have considerable experience with regards to helicopter winching. The likelyhood of one "falling out" of a Nato Strop I find quite laughable frankly as this is a massive slur to their abilities and knowledge. At this time, we do not know enough about the events to draw conclusions, but a cable cut or concious act by the rescuer seem reasonable possibilities. Certainly I would not want to be attached to 21000 lb of whirling metal and fuel which was in an emergency situation.
Tecpilot,
You mentioned problems with the casualty being wet and slipping through the strop. The nato strop does not rely on friction between it and the occupant and so on the occasions I was winched out of the sea, I felt perfectly safe. I never noticed any change in performance of the strop whether I was wet or dry.
Just my thoughts
Obs cop