I was a very good friend of the founder of the world wide disability movement, Ed Roberts. (Ed was actually one of two founders.)
Over the more than two decades that I knew Ed he had several attendants. He needed several because he could not breathe without a machine or an iron lung at night. He had very limited movement. It was the result of teenage polio.
The subject related to Ed came up recently when a friend told me about a year he spent being a caregiver to a woman with severe disability. At the end of the year my friend discovered his own case of disability. He has since been able to treat it and recover.
That is when I recalled that three of the caregivers for Ed had become recipients of disability funds themselves. They had become disabled after working full-time with a disabled person.
It is possible that people saw the mechanism for getting government grants in the disability field and wanted some for themselves. I don't think this was the case. I saw no one faking their uncomfortable new condition.
I think we have a real mystery about a very unusual issue.