NigelH,
In my warehouse we handled coils of steel up to 25000kilo(25t) whilst the overhead crane used a true crane required wire rope,.. the pick up was done with a continuous Nylon Sling wrapped in a sleeve like can be seen in the picture prior to the weight lifting off. Once weight is applied the thousands of nylon fibres each take part of the strain and allow such massif weights to be easily manouvered into storage or onto a cradle for transport, The sleeved lifting line seems to me to be one of this new type of lifting line fastened into a shackle point within the unique wrecking ball, the benefits of this type of line is unbelievable strength very light to handle, but very easy to handle by just a pair of gloved hands on connecting.
So if that is the case here, there will be no transfer of impact shock at all, only if the ball became caught and this allowed the line to become slack then the dropped weight would be FULL weight transferto heli.
Peter R-B