Charlie Lewis was in charge of the International Boxing Federation Pan Pacific Super Featherweight title fight on September 11, 2015, at Ingleburn RSL in which professional boxer David "Davey" Browne was fatally injured. Browne died in hospital from bleeding on the brain following the withdrawal of life support four days later.

At an inquest at the Coroner's Court in Glebe on Wednesday, Mr Lewis said he had no training in how to identify a serious head injury and "a little" training in spotting concussion.

He described his practice for assessing boxers' fitness, saying it was a method he had been taught by senior referees when he first began officiating bouts.

"I look them straight in the eye and I talk to them. If their eyes are clear - not glazed, or moving - and looking straight back at you [they are fit]," he said.

"I say, 'How are ya mate?' and if I'm really worried I ask, 'Where are you?' " he told the inquest.

Mr Lewis said he always talked to both competitors before a fight "so I know how they sound".

Earlier in the inquest, neurosurgeon Professor Brian Owler gave expert evidence that Browne was in a "perilous state" and probably concussed before the blow that killed him in the 12th and final round.

Whether the bout should have been called off earlier - either in the 11th round when Browne fell against the ropes as the bell rang or in the sixth round, when he was first knocked down - is being examined by Deputy State Coroner Teresa O'Sullivan.

Under questioning from counsel assisting the coroner Kristina Stern, SC, Mr Lewis said he felt Browne was "hurt to the body" but not the head and "not impaired" following the knockdown in round six.

But he agreed in the 11th round Browne was "saved by the bell", which is against boxing rules.

Video footage of the fight shows that, as the bell went for the end of the penultimate round, Browne fell back against the ropes - technically considered a knockdown.

He had already had one knockdown during the round but had recovered to his feet.

Under the rules, Mr Lewis should have called a mandatory eight count - a period following a knockdown that allows the referee time to decide whether the boxer can continue.

However, Mr Lewis didn't do this and Browne and his Filipino opponent Carlo Magali??? went to their respective corners and took their minute break.

"It was right on the bell. You've got a split second to decide whether it's a knockdown and penalise or whatever or let them have their minute break.

"It's a timing thing, it's not an exact science, it's just one of those decisions that you make," he said.

Later on Wednesday, Dr Peter Lewis, a worldwide expert in combat sports medicine, said it was unreasonable to mandate the attendance of an ambulance and paramedic at all professional and amateur boxing matches.

"The injury rate of boxing is not so high that an ambulance is required to be present at all times. You can't have an ambulance everywhere. It just becomes too expensive for the community," Dr Lewis said.

"It is not common that we have to deal with a significant head injury ringside."

However, Dr Lewis said there should be an oxygen cylinder ringside at every fight.

Earlier on Wednesday, the physician on duty at Browne's fight, Dr Lawrence Noonan, said no one present raised with him any concerns about Browne's wellbeing or safety during the bout.

Dr Noonan did not assess Browne during the break before the last round, but asked him if he was "all right".

Dr Lewis said this was not adequate as most professional fighters will indicate they're fine to fight on if asked.

The inquest continues.