His daughter is now rushing home from Queensland trying to get back to say goodbye before his life support is switched off.
Mr Haddon went in an ambulance to Modbury Hospital last week bleeding and with severe abdominal pain.
He was told he had a urinary tract infection and was sent home.
But after his condition worsened on Saturday, he was rushed back to hospital, where doctors began removing blood clots.
His family said doctors and nurses were told each time he was in hospital that’d he’d had the AstraZeneca vaccine.
They are now arguing that the vaccine and his symptoms mean medical staff should have checked for blood clots from the outset.
“If he had proper treatment on the Thursday night, he would definitely be in a better position than he is right now,” his daughter Michelle told 9News.
South Australia’s Deputy Chief Public Health Officer Michael Cusack said it was “highly unlikely that his recent illness is linked to the AstraZeneca vaccine”.