Mr Parry could not be reached yesterday. The Press reported last year that he quit in 2013.
Mr Hill said Dr C committed a "serious error" when he passed surgical tape through the major vein leading to the 80-year-old's liver. That was during an emergency operation to find and repair the cause of bleeding following surgery to remove the gallbladder and repair a hernia.
The error caused further bleeding and despite extensive resuscitation efforts, Mr Nicholls died.
A post-mortem examination attributed his death to blood loss from both the vein and a liver artery that appeared to have been damaged during the initial surgery.
Mr Hill said the patient's blood pressure started to drop about an hour after the first operation. More than an hour later, the surgeon arranged an ultrasound, which showed internal bleeding, and decided to operate again.
The commissioner's surgeon-adviser, David Schroeder, said the ultrasound was unnecessary and "probably delayed things more". The delay and prolonged low blood pressure were major departures from acceptable care, Mr Schroeder said.
Mr Parry, whose qualifications are from South Africa, started at Wairau Hospital in 2010.
The following year a patient he operated on died from bleeding after gallbladder-removal surgery, which started as keyhole but was converted to an open procedure.
During the internal investigation, two more cases came to light of common bile duct injury during keyhole gallbladder operations.
Mr Parry stopped doing all keyhole surgery pending a performance review.
He offered Mr Nicholls open surgery, which Mr Hill considered appropriate because of the patient's earlier surgery to repair an aortic aneurism and because he was also going to have a hernia repaired.
But the surgeon did not tell the patient of the "voluntary restrictions" on his practice, a breach of the code, Mr Hill said.
"A reasonable consumer in [Mr Nicholls'] circumstances would expect to receive relevant information about restrictions on his surgeon's practice, even if those restrictions arose out of a voluntary agreement."
They might have influenced his decision to have the surgery done at that time and hospital, Mr Hill said.
The commissioner found the Nelson Marlborough District Health Board in breach of the code, too, saying it held ultimate responsibility for the failures of several staff to recognise the risks to the patient and to advocate for him.
Board chief executive Chris Fleming expressed his apologies to the dead man's family. The board accepted the commissioner's finding and had taken steps to address the recommendations.
Chief medical officer Dr Nick Baker said lessons had been learned and processes were tighter as a result.
