"So if he kills a hostage we're not going in?"

The leader of a police tactical assault team recalled asking his boss the question on the night of the Lindt cafe siege.

"He said no, the call has to come from higher command."

The alleged exchange seemed to show even death may not have been enough to prompt immediate police action.

But now the officer known as Delta Alpha has changed his story after reading a media report about confusion among police, he told an inquest on Monday.

During the 2014 siege, Delta Alpha was in charge of devising a surprise assault known as "deliberate action", or DA.

He also stood ready to be deployed as part of an "emergency action" plan, or EA. The inquest has previously heard police had conflicting ideas about what would trigger the emergency response.

Delta Alpha said that at the start of the siege he had assumed the standard trigger was in place: imminent threat of death or serious injury.

But a conversation with the deputy tactical commander during the siege had led him to believe there was no automatic trigger, he said in a January 2015 statement. He recalled this being "unusual" and agreed in court it "made no sense".

Then on Monday, Delta Alpha said he and the deputy tactical commander might have been referring to different plans, confusing the EA and DA.

A barrister representing the family of killed hostage Katrina Dawson pressed Delta Alpha on his new interpretation of events.

"When you read a newspaper report you decided to review and revise your account, correct?" Michael O'Connell, SC, asked.

Delta Alpha agreed he had but could not recall which witness the news report concerned. "It was something about confusion over triggers."

Delta Alpha said between giving his statement and testifying in court, he had also read police documents that set out the standard trigger for emergency action.

The deputy tactical commander testified last week he had always thought an immediate threat of death or serious injury was the trigger.

In other evidence, Delta Alpha said he had been unable to see when he became the first of his team to enter the cafe. One of his officers had thrown a flash-bang distractor that bounced off a door.

He took off his night-vision goggles and did not put them back on before crossing into the stronghold. "Because it was so black, the Tango [target] could have been standing one metre inside and I wouldn't have been able to see him," he said.

Delta Alpha said after manoeuvring into the cafe he could see what looked like a pillar.Turning on the torch attached to his assault rifle, he realised this was a female hostage dressed in black.

Man Haron Monis was standing directly behind her, facing officers entering through the main entrance to the cafe.

"I said to the female, and indicated with my left hand, 'Get down, get down, get down'." She did not. Delta Alpha said he moved into a kneeling position for a clearer shot at Monis.

"I distinctly remember thinking to myself that I needed to shoot him."

But by the time he had turned on his torch again, Monis was dead, shot by another police team, he said. Delta Alpha rated the probability of crossfire on the night as "high" as multiple assault teams had entered simultaneously.

The inquest continues.