Years ago Canada did not allow electric down riggers unless you had a note from a doctor. It was easy to tell a doctor "cranking a downriver may cause carpal tunnel" virtually every boat had electric down riggers (except mine!). They finally just made them legal.I'd think that would be a stretch for even the most unscrupulous individuals.
Let's see what story it takes for a "fishing disability"? "It hurts my back when I climb out of a boat"? "I could drown if I fell climbing in and out". It puts a lot of pressure on a doctor to deny a "disability". They could be liable for an accident.