Overnight "graveyard shifts" at an SA Pathology laboratory were scrapped to prevent tired scientists making mistakes, an inquest into the death of a man who was misdiagnosed with lung cancer has heard.
Broken Hill man Dennis Charles Jackson was incorrectly diagnosed with lung cancer before he died from pneumonia in January 2019.
An inquest examining the 67-year-old's death has previously heard his biopsy sample was cross-contaminated with the cancerous tissue of another patient at an SA Pathology laboratory.
Mr Jackson went on to have unnecessary surgery to remove part of his lung, which caused complications including difficulty in eating, drinking and swallowing.
Senior consultant pathologist Sophia Otto, who is now SA Pathology's clinical service director, gave evidence at the inquest on Friday afternoon.
She said Mr Jackson's biopsy sample was processed overnight, and since his death the "graveyard shift" had been scrapped to prevent scientist fatigue and error.
Dr Otto said she "remained concerned" that an unnamed scientist who worked on Mr Jackson's sample was prone to mistakes late in the night.
"I was concerned this individual was fatigued, that the individual's work flow was interrupted because of course there are very few people on the overnight shift," Dr Otto said.
"I also worry about the staff member wearing the same protective equipment."
Earlier this week, the inquest heard it was considered "satisfactory" at the laboratory to just wipe down rather than "burn" the forceps used while obtaining and analysing biopsy samples.
Caroline Smith, who worked at SA Pathology at the time, told the inquest she was "surprised" to hear lab equipment had been wiped down between tests, instead of being sterilised with a Bunsen burner.
Dr Smith said it was not clear the sample given to her was contaminated, because of the lack of live tissue surrounding it.
She said due to the absence, she could not confirm that invasive cancerous cells could be proven, which would have led to a second biopsy.
Dr Smith said she outlined this in the body of her report, but she could have been clearer.
"In retrospect my report would have been better if I had qualified it in the diagnosis line," she said.
The court earlier heard doctors at the Royal Adelaide Hospital acted on her report, assuming the sample showed invasive cancerous cells, which led to the unnecessary procedure.
Dr Smith also told the inquest that no official communication was given to staff generally if a cross-contamination did occur at SA Pathology.
"Many of my colleagues knew about [Mr Jackson's] case through I can only say "corridor conversation" — but there was no formal notification to everyone that a contaminant event had occurred," she said.
The inquest heard SA Pathology has since put in place more checks and balances to prevent cross-contamination.
The inquest before Deputy State Coroner Ian White continues next week.
