I cannot fathom that a person with the skills, resources, and tenacity to DIY a helicopter could not lay their hands on at least a car seatbelt and a scooter helmet during the course of the project. I wouldn’t be surprised if the crash scene was within sight of both of those items.

“Aviation in itself is not inherently dangerous. But to an even greater degree than the sea, it is terribly unforgiving of any carelessness, incapacity or neglect.”

Which isn't a lot and I think this is an unfortunate oversight, but I can see it being a bit difficult to do properly.

Of course, doing it improperly with a rope would probably have been better than not at all.