Robinson records Mitchell's cause of death as "septicaemia secondary to aspiration pneumonia in the context of bowel obstruction''.
He should have received an abdominal examination and "urgent admission to hospital''.
When Mitchell died he "was not a well man'', Robinson writes. At the time of his death, he suffered from a host of conditions, his mobility was limited and he was dependent on a scooter.
"I immediately recognise Mitchell's comorbidities, and the uncertainty of outcome even if he had been a surgical candidate. It cannot therefore be definitely said that his death would have been prevented, but it is clear that an opportunity was lost.''
When Mitchell went to the after-hours general practitioner he was having abdominal cramps and had vomited that morning after not having eaten, nor having had a bowel movement, for two days.
He was suspected to have a "mild gastric upset'', possibly a virus, and Mr Mitchell was sent home with anti-nausea medicine and told to return to the doctor if his symptoms persisted.
Two days later, after returning from the toilet, he slumped forward and became unresponsive.
Mitchell was pronounced dead by ambulance staff.
A nurse who attended noticed he had vomited faecal matter. His regular doctor expressed concern.
And because the cause of death was unknown it was referred to the coroner.
Robinson sought to confirm the cause of death, and the circumstances surrounding it; whether the death could have been prevented; and whether there were any appropriate recommendations.
Pathologist Dr Leonard Wakefield conducted an autopsy two days after Mitchell's death.
