The Ocean's Eleven star passed away in August 2008, following a prolonged battle with pneumonia.
His grieving widow, Rhonda McCullough, filed a wrongful death lawsuit against dermatologist Rene M. Earles last week (ends30Jul10), alleging he overlooked signs of respiratory failure when Mac visited him at his Chicago, Illinois clinic on 17 July, 2008.
She believes the star should have immediately been admitted to hospital for further examination, instead of being kept at the clinic - which she alleges could have saved his life.
Legal papers filed in Chicago's Cook County Circuit Court state, "(Earles) failed to recognise and act upon abnormal vital signs and signs of respiratory failure."
But Earles has defended his actions, claiming he advised Mac, who appeared weak when he turned up with a fever and a rash, to go straight to hospital after learning from his other doctor that he had been diagnosed with pneumonia in both lungs.
It was then that the 50 year old was taken to an emergency room by his chauffeur and treated by hospital doctors, reports the Chicago Sun-Times newspaper.
Earles adds, "He didn't die the next day, he didn't die in two days. He died in two weeks and he got over his original strain of pneumonia. He got another strain of pneumonia while he was in the hospital."