Rescuers wear helmets
The rings we use weigh 365 grams each, there are three of them
Those rings falling 150 feet is not going to kill somone wearing a helmet. If it hit them its going to leave a nice welt, possibly beak some of the weaker bones if it contacted them.
I find it ironic that just a month ago there was a HEC accident where (from the sound of things) the lineman could have been saved if the pilot DID have the ability to realease him, and now after some of the same people saying there should be no means of realease nor no practical means of release.
There should be a means of release, on the flight controls protected against inadvertant release by double actions. If the pilot went IIMC or got LTE and started spinning and the rescuer did in fact ask to be released the pilot did the right thing at that point in cutting him loose.
Essentially he relied on the rescuers judgement that he was in a position to land without serious injury.
Whether the pilot (or the company) did the right things getting into that situation is a different point entirely. From the sound of things, they did not.