The woman, Yan Wang (42), was killed when the jet-boat in which she was a passenger apparently struck a sandbar in the Kawarau River and flipped, about 2.45pm on September 25 last year.
Mrs Wang was trapped under the upturned boat and her body not located until about 90 minutes after the accident.
St John paramedics tried unsuccessfully for 45 minutes to revive her, before declaring her dead at the scene.
However, St John Central Otago district operations manager Pete Grayland was yesterday forced to defend his staff, after questions about initial care were raised in a debriefing paper on the incident released by the Southland District Health Board.
The paper confirmed a second attempt had been made to revive Mrs Wang after her body was delivered to Queenstown's Lakes District Hospital, SDHB chief operating officer Lexie O'Shea confirmed last night.
The reason why the second attempt was made was a "clinical decision" and not one that she was able to discuss last night, she said.
However, Mr Grayland told the Otago Daily Times his staff had done "everything they could" to save Mrs Wang.
"We got called to a tragic scene and we did what we could," he said. "My guys did everything they could in the power of their training to revive her, but she was dead."
The St John staff - including an advanced paramedic - used a combination of CPR, oxygen therapy and a defibrillator at the scene, and checked for signs of life repeatedly, during their 45-minute effort, he said.
Mrs Wang was transferred to the hospital, where doctors decided that questions over initial care meant a second attempt to revive her should be made.
Mr Grayland said the decision was made "at least 30 minutes" after Mrs Wang was first declared dead, and after St John staff had left the hospital.
Asked why, he said: "I can't answer that either."SDHB staff were not able to provide a copy of the debriefing paper last night, following its release under the Official Information Act 1982 to Queenstown's Mountain Scene newspaper.
Ms O'Shea said the debriefing was something undertaken whenever anything "out of the ordinary" took place during an incident.
In this case, about 15 items had been identified that needed "clarification" with St John and others involved.
Asked what they were, she said she was unable to comment without a copy of the debriefing report in front of her and the debriefing was "a work in progress".
"There're obviously areas where we are going to be continuing dialogue with other agencies.
"There will be things we could have done differently and we will implement those.
"There are things we would not have ever been able to change," she said.
