The parents of murdered Lindt cafe manager Tori Johnson have slammed a senior police commander as an "absolute disgrace" after he described the Sydney siege as a "high stakes game".

Rosie Connellan and Ken Johnson stormed out of the inquest after the police forward commander said gunman Man Haron Monis had the same rights as the 18 staff and customers he took hostage in the Martin Place Lindt Cafe in 2014.

Ms Connellan yelled "you're an absolute disgrace" as she walked out of the inquest.

The commander, who cannot be identified, made the statement under cross examination by Gabrielle Bashir SC, the barrister acting for Mr Johnson's family.

Ms Bashir put it to the commander that police had always had a trigger to force entry to the cafe because the belief Monis had a backpack bomb and a detonator meant the hostages were in imminent or immediate danger throughout the entire 17-hour ordeal.

The commander conceded the presence of the bomb created an imminent risk but rejected suggestions police simply let the siege play out without intervening.

"It was a high stakes game," the commander said.

"There's a lot at stake for the hostages and police. I don't accept the position that I was sitting, waiting for that trigger point to be reached.

"These are difficult bloody decisions, your honour, and I did my absolute best on the night."

Ms Bashir then interrupted the commander and asked him to apologise to Tori Johnson's family for using the word game.

Police at the scene during the Sydney siege in 2014. ( Audience submitted: Peter Morgan )

"I accept game may not be the right word but there's a lot at stake here," he replied.

"I've got to make some crucial decisions to get the best outcome and that's what I did on the night."

The commander then told the inquest his mission during the siege was to save the lives of the hostages and Monis.

"I couldn't ignore Man Monis as an individual. He had the same rights as any other person," he said.

The inquest has previously heard the forward commander gave the order for police to storm the cafe just moments after he heard a sniper call "hostage down, hostage down" over the police radio.

Monis forced Mr Johnson to kneel at 2:06am and shot him through the back of the head at point-blank range at 2:13am.

Monis may have been trying to build 'street cred' before jail time

Monis was on bail on a charge of being an accessory to the murder of his ex-wife. ( Supplied: NSW Justice )

Earlier, the commander said he was advised Monis may have been trying to make one last public stand before he was imprisoned on criminal charges.

Monis was on bail awaiting trial on a charge of being an accessory to the murder of his ex-wife and about 40 sexual assault charges at the time of the siege.

The commander told the inquest a police psychiatrist said Monis might be attempting to "build some street cred or jail cred" and the siege was a "final posturing" ahead of his incarceration.

The inquest heard that advice came just an hour before Monis executed Mr Johnson.

IS situations 'begin with violence, high levels of death'

An independent review of the siege and its management by a UK panel of experts found: "in [Islamic State] inspired sieges the maximum chance of survival of the hostages is achieved through early intervention by police, as opposed to the hope that given time hostages will be released or escape".

A black flag is pressed up against a window during the Sydney siege. ( Supplied, file photo )

Hostage Katrina Dawson was killed by shrapnel when tactical officers stormed the cafe in the early hours.

The barrister for Ms Dawson's family, Michael O'Connell SC, questioned the commander as to whether police should have stormed the building sooner given the panel's findings.

The commander told the inquest he knew Monis claimed the siege was an attack on Australia by Islamic State [IS] and that the gunman had requested an IS flag.

But he thought the attack had many hallmarks of a domestic siege.

"It was always a terrorist incident in my mind but I had an internal conflict," he said.

"Our experience internationally is IS does not have sieges, they have active armed offender situations."

"They commence with violence, high levels of death, whether by a person-borne bomb or automatic gunfire - they are not siege situations.

"I can't think of any IS-inspired event around the world that has been a stronghold situation."