The Avmed crew should have been run out of town on a rail after the - Hempel - fiasco
A fiasco indeed. Much blame all round: The pilot for knowingly flouting the conditions of his licence. CASA (not just AVMED) for allowing him to repeatedly break the rules over decades (although I'm not sure what they could have realistically done other than posting an armed guard next to every aircraft that he might have tried to fly). His DAME and specialist for deliberately covering up his condition for so long. Every single one of his colleagues and those that knew what he was doing, and chose to ignore it.
In the end, a paying passenger, who had no knowledge of the risks they were accepting ended up dead.