A young man deemed in need of an immediate transfer to hospital after a drug overdose at a New South Wales music festival was not put in an ambulance for an hour, an inquest has heard.

Joseph Pham, 23, died from MDMA toxicity after attending Defqon.1 at Sydney International Regatta Centre in Castlereagh in September 2018. There were 30,000 patrons at the sold-out event by 6pm.

The evidence came on the second day of a two-week inquest into the deaths of six Australians from drug overdoses at various NSW music festivals over a one-year period.

On Tuesday the inquest heard that Dr Andrew Beshara was managing two “significant patients” including a psychosis post-MDMA ingestion and an asthma attack when Pham arrived critically ill at the medical tent. This was at about 7.34pm.

An ambulance wasn’t ready to take him to Nepean hospital until 8.35pm, counsel assisting the coroner, Peggy Dwyer, said on Tuesday.

Pham was unresponsive with dilated pupils and was also experiencing “trismus” (spasming of the jaw muscles) as a result of his drug ingestion.

“His jaw was essentially wired shut, his arms and legs were tensed up and he was very stiff,” Beshara told the NSW coroners court in Lidcombe.

“Essentially from the moment we received him, he would need to be transferred.”

Beshara was one of two Event Medical Services doctors on at the time. He conceded there was a lack of coordination between EMS staff and NSW Ambulance.

“That was definitely the biggest event I’ve ever done ... there should be a lot more staff,” he said. “If you have two emergency beds, two doctors per bed would have been a lot more feasible.”

The doctor said having “a second set of hands” per patient would have made him feel a lot more comfortable.

One of Pham’s school friends, who cannot be identified for legal reasons, earlier testified he was shocked when the 23-year-old told him he’d taken three or four pills.

The young man said Pham told him he “had some in his bag” as they travelled to the event.

“I don’t like talking about drugs so I let him do what he wants to do,” the man said. “That event is, like, known for drugs and his facial expression gave it away.”

He said he thought the purple-coloured pills would have been MDMA because “when you go to those sorts of events, that’s what everyone takes”.

Diana Nguyen, 21, was the second fatality at that same festival.

She was carried into the medical tent by a security officer minutes after Pham. Their deaths are among six being investigated by deputy state coroner Harriet Grahame.

Nathan Tran, Callum Brosnan, Joshua Tam and Alexandra Ross-King also died from MDMA toxicity or complications of MDMA use at NSW music festivals between December 2017 and January 2019. They were all aged between 18 and 23.