Last year, I read a report by some anthropologists that may be evidence of your example. Studying the skeletons of people who lived very long ago (over 20,000 years ago, if I recall the report accurately), they found examples of people who lived long after sustaining severe, crippling injuries or with arthritis. The implication was that the other members of this person's group kept him alive, perhaps out of compassion. Another possible explaination was that this person had some useful skills such as your arrowmaking example that caused the others to keep this person alive long after he couldn't hunt any more.

A quick web search found this article among others on the topic.

Although he was born into a savage and brutal environment, Shanidar I man provides proof that his people were not lacking in compassion. According to Stewart's findings, he was an individual who lived to the relatively old age of forty years, a spry old man for a Neanderthal - equivalent to a man of about eighty today. He was plagued by arthritis, which seems to have been a rather common ailment among Neanderthals - and no wonder, considering the kind of life they led. As a case of rehabilitation, Shanidar I was a prime example. Not only did he possess a disability from the day he was born, but he must have been blind in the left eye. Stewart's examinations disclosed that the right arm, collar bone, and shoulder blade had never fully grown from birth. Furthermore, there was extensive bone scar tissue on the left side of his face. And as if this were not enough, there is evidence that the top right side of his skull had received some damage which had healed well before the time of death. In short, Shanidar I - or 'Nandy', as we called him around the dinner-table - was at a distinct disadvantage in an environment where even men in the best of condition had a hard time. He could barely forage and fend for himself, and we must assume that he was accepted and supported by his people up to the day he died. Any manpower must have been an asset to this ancient little community, especially since it undoubtedly took group activity to hunt the gregarious beasts of the wild. That 'Nandy' made himself useful around the hearth (two hearths were found very close to him) is evidenced by the unusual wear on his front teeth. It presumably indicates that in lieu of a right arm, he used his jaws for grasping, while manipulating with his good left arm and hand.

Clearly, this man couldn't hunt with his disabilities, but the other members of his group kept him alive for a reason.