We will never know
It's all very well saying the pilot had a moral responsibility to avoid those on the beech but it is a very thin beach and highly probable that the area appeared clear when it was selected as a forced landing area.
No one would aim at a person on the ground or a populated area so it is highly likely the pilot aimed at a clear area and the victim simply walked into that area unaware that a silent aircraft was about be forced to land on it.
That's why it is called an accident, unfortunately lawyers have created a society that thinks accidents can't happen because without someone to take the blame there is no claim.