For me the mystery is how the deceased diver could have evaded the careful search of an area close to the original dive location of a team of divers over a period of even one to two days.
Unless he was concealed and stuck deep under a ledge or in a cave. Possibly after suffering a medical emergency. If 3 divers were all within a 10m radius (which I doubt) then the vis must have been pretty bad for noone to see anything especially something like a fatal shark attack in open water. To me any other explanation seems unlikely, how else could you explain such an extensive search failing to locate a body which then miraculously happens to appear in that exact spot with bite marks several days later.
In the past Fisheries WA scientists have been able to confirm this within a few days of a fatal attack and identify the type of shark responsible for the attack without the need for an inquest
Maybe because this isn't a fatal shark attack? Except in your mind perhaps.
From the last article you posted: "Police said his death would be examined by the WA Coroner but initial investigations indicated that he might have shark bites. The friends did not observe any attack and the cause of death is unclear at this stage".