There would be no recourse for any pilot/operator to get sued for not going to retrieve someone whom consequently died as a result of not being assisted in a timely manor.
It couldn't be definitively proved that such a delay in getting to that person was the soul cause of death & it would take a very brave coroner to say such a thing I reckon. I know we lost a few over the years whom passed away the night/day during a period when we simply couldn't get there due safety reasons.Whether that delay had any hastening impact on their deaths will never truly be known but we did our best.
There was a saying that I adopted,no point in running an unnecessary high risk which could result in the deaths of say 3or 4 to save just one!
Wmk2