An inquest has heard three Australian soldiers killed in Afghanistan in 2012 probably would have survived if they had been wearing armour and helmets.

Three Australian soldiers killed in an insider attack in Afghanistan would probably have survived if they’d been wearing body armour and helmets, an inquest has heard.

A workplace health and safety expert has told an inquest into the deaths of Lance Corporal Stjepan Milosevic, Sapper James Martin and Private Robert Poate that heavy body armour and helmets would likely have given the men vital protection when a rogue Afghan National Army soldier turned his weapon on them.

The rogue sergeant, named Hekmatullah, fired a machine gun into a group of Australian soldiers playing cards inside a patrol base in Oruzgan province in August 2012.

The Brisbane inquest has heard the Australian soldiers had been allowed to take off their 34kg body armour and wear gym clothes as they mingled with Afghan soldiers at the desert base that night.

Doctor and occupational health and safety expert Graeme Peel, who designed a risk assessment program for the army in 2005, told the inquest the best way of mitigating the danger of a so-called green on blue attack was to isolate Australian soldiers from their Afghan counterparts.

Failing that, he said, the next lines of defence were troop training in avoiding attacks, and helmets and body armour.

Dr Peel said the three soldiers died from chest wounds or, in one case, a head wound.

“The location of those wounds made it more likely than not that standard issue body armour would have protected those soldiers to a level where those wounds were not likely to have been fatal,” he said.

Under cross-examination Dr Peel agreed the armour would have been hot and burdensome, but said the troops could only have safely removed it if they’d been separated within the base from the Afghan soldiers.

Meanwhile the inquest heard an American general involved in a Joint Casualty Assessment Team investigation into the soldiers’ deaths was “gobsmacked” to learn Australians were living so close to the Afghan National Army forces at the patrol base, named Wahab.

The former head of the dead soldiers’ task force, Colonel Trent Scott, told the inquest the American general hadn’t been familiar with the Australian method of mentoring the ANA, which Col Scott said was recognised as more successful by senior coalition officers.

In at times heated exchanges with the lawyer for Pte Poate’s family, Col Scott denied security at the base was inadequate, and said nothing could have protected the three soldiers from the rogue Afghan soldier.

However the colonel conceded it would have been better to have more guards watching over the soldiers and admitted he’d initially wanted to know why there hadn’t been.

Witness evidence to the inquest is expected to finish on Friday before lawyers present closing submissions at a later date.