Getting pax onto a seaplane and slipping mooring lines requires nifty footwork and if the pilot was affected by exposure from prior flights or burning pizzas then it would have been obvious at that stage. My question to any aviation med people (or even doctors who like carbon monoxide cases) is whether or not symptoms and debilitation are in direct proportion to blood CO content, ie., can you get a 'safe amount' of blood CO beyond which things begin to fall apart ?