The most senior doctor at Sydney's deadly Defqon.1 music festival had two doses of a potentially life-saving medication and no clear figures on the amount of other drugs on hand.
Sean Wing was one of the two doctors at the medical tent of the September 2018 festival, where Melbourne woman Diana Nguyen, 21, and Sydney student Joseph Pham, 23, took multiple MDMA pills.
Both presented unconscious and critically ill to the medical tent and later died in hospital.
Dr Wing on Friday told a NSW coronial inquest, he brought a range of drugs to the festival, basing the quantities on a formula estimating how many of Defqon.1's 30,000 attendees would fall ill.
But no full count of the drugs was ever produced, he said.
Asked by Deputy State Coroner Harriet Grahame whether it wasn't possible for him on the day to have known what was available, he said: "I agree there was not a comprehensive count of the exact things that went into the tent."
The Brisbane-based emergency registrar said he took one dose each of two muscle relaxants that help getting a tube down the throat of critically ill patients.
Rocuronium was used on Mr Pham while Ms Nguyen received succinylcholine, which Dr Wing said was "not the ideal drug but it can be used".
He agreed Ms Nguyen would have received rocuronium if it was available.
Giving both doses meant the one-day festival, where almost 700 people presented to the medical tent, was without medications to assist intubations after 8.50pm.
Dr Wing defended the decision to be one of only two doctors on-site, saying that was "within the realm" of acceptable staffing and festivals half the size operated with one doctor.
"To intubate two patients (at a festival) was previously unheard of," he said.
He was critical of Dr Andrew Beshara who'd he assumed was capable of performing intubations unassisted.
Dr Beshara earlier told the inquest he'd have preferred four doctors at the festival.
One of the paramedics present as both Ms Nguyen and Ms Pham lay critically ill on beds in the festival's crowded and loud medical facility, slammed the management of the private medial provider.
"I found it extremely difficult to deliver care to (Mr Pham) as there was no team leader established," Mr Mascorella told the inquest on Friday.
"The doctors were giving the patient medication during (his cardiac arrest) that we weren't aware of.
"I found the lack of leadership and crew resource management of the Event Medical Services crew to be completely abhorrent."
Mr Mascorella said private contractor EMS, which contracted doctors Wing and Beshara, had assured him paramedics would only be needed for transport.
But he said by 8pm, when Mr Pham and Ms Nguyen were being treated, the medical tent staff were overwhelmed.
Mr Mascorella added there was no right of way for ambulances to get to and from the medical tent in the centre of the festival grounds.
The deaths of Mr Pham, Ms Nguyen, Nathan Tran, Callum Brosnan, Joshua Tam and Alexandra Ross-King - all aged between 18 and 23 - are the subject of the inquest at the NSW Coroners' Court.
All died from MDMA toxicity or complications of MDMA use at NSW festivals between December 2017 and January.