Fatherly instinct drove an Adelaide doctor to help his daughter over a man in a far worse condition after the pair had overdosed on heroin, a coroner has heard.
Dr Jack Kerry has given evidence to an inquest into the death of Lucas Adam Pike, who overdosed inside Dr Kerry's CBD medical practice in March 2016.
Dr Kerry told the coroner on Thursday he found Mr Pike and his daughter, Athena Kyriacou, unconscious and instinctively began CPR on her.
"I went straight to my daughter," he said.
"I didn't know whether she was going to come out of it and I didn't know whether Luke Pike would come out of it."
He agreed Mr Pike was in a far worse state than his daughter but said the man had "gone past the point of no return".
However, Dr Kerry said Mr Pike's condition was not a factor in his decision not to work on him.
"If Luke Pike had been the only man in that room... I would have been straight onto him straight away," he said.
Dr Kerry directed another man, Mark Campbell, to perform CPR on Mr Pike and briefly took over when Mr Campbell left the room.
Paramedics arrived a short time later and treated Mr Pike, but they were unable to revive him and he died at the scene.
Ms Kyriacou was taken to hospital for further treatment.
The coroner has heard Ms Kyriacou, Mr Pike and Mr Campbell had bought $150 worth of heroin and visited the Hindley St practice of Dr Kerry, where Ms Kyriacou worked as a phlebotomist.
Earlier in the week, counsel assisting the coroner Naomi Kereru said police could have missed an opportunity to lay charges over the heroin supply.
On the night of Mr Pike's death, officers searched a Kurralta Park home after they established a link between his overdose and the address.
They seized drugs and cash, leading to the eventual conviction of a man on trafficking charges.
Ms Kereru said a syringe taken from the medical practice was never recorded in the police report or forensically tested, therefore could not be linked to the supply.
The inquest continues before Coroner Mark Johns.