Mr Barnes, of course, does not seek to pose or answer such a blunt question.

Instead, his long-awaited report into the Lindt cafe siege of December 2014 walks a judicious, at times fine line between recommending sweeping systemic changes to how police respond to future terrorism events, and seeking to avoid laying blame on individual officers for clear failures on the night.

In remarks introducing his mammoth 500-page report, he commends the bravery of the Tactical Operations Unit officers who stormed the cafe, and makes a point of stating none of their superiors - who carried the " burden" of command - had shirked their duty.

But "mistakes cannot be papered over", he said - and he has identified many, not just on the part of police but on the part of other agencies that played a role during the siege.

In particular, the coroner believes the "contain and negotiate" (or wait-and-see) strategy that police adopted on the night is almost certainly outdated in an era of IS-inspired terror.

Police waited too long to enter the cafe, and should have done so when Man Haron Monis first fired his sawn-off shotgun as a group of hostages escaped at 2.03 am. A precious 10 minutes was lost before cafe manager Tori Johnson was executed by Monis at 2.13 am, triggering the storming of the cafe.

Commanders also erred in not approving a so-called deliberate action plan that would have given tactical officers the chance of catching gunman Monis off guard if such an opportunity had presented itself. However their decision not to authorise such a plan was a decision that was based on "flawed advice", Mr Barnes finds.

Significantly, new Police Commissioner Mick Fuller has taken this criticism on the chin, admitting on Wednesday that with the benefit of hindsight, "we should have gone in earlier."

Some of Mr Barnes' heaviest criticism is reserved for police negotiators, who did nothing to change their tactics during the night, despite the long stalemate that developed as Monis refused to engage negotiators directly. Nor did their superiors press them hard enough to come up with fresh approaches as the siege dragged on. Sensibly, Mr Barnes wants a specialist negotiation unit to be set up for dealing with future terrorism incidents.

In addition, a consultant psychiatrist who helped direct negotiations on the night overstepped his role, contributing to police grossly underestimating the threat that Monis posed because of "erroneous and unrealistic assessments".

These are just some of a litany of shortcomings Mr Barnes has identified, which will take police weeks, if not months, to work through.

Significantly, he has also observed that although the snipers deployed on the night had no real opportunity to take a shot at Monis, they were hamstrung in any case by not being sure about when they could legally try to neutralise him. Their belief that they did not have lawful authority to take Monis out was "unduly restrictive", the coroner says, urging that their right to use force in future be more "clearly defined".

And although he found that calling in army commandos was not the best option on the night, the coroner believes the Australian Defence Force could have rendered more assistance. And he thinks there should be a review of the very high threshhold that currently applies before the army is called in during a terrorist incident.

As well, in a move that will no doubt draw ire from privacy advocates, Mr Barnes says the government should consider whether NSW Health should more readily share information so that "fixated lone actors" can be identified and monitored earlier.

Former police chief Andrew Scipione has largely escaped criticism, as has Deputy Commissioner Catherine Burn.

But bail decisions made in late 2013 and 2014 when Monis was before the courts on sexual assault and accessory to murder charges come in for criticism, with Mr Barnes finding that several key opportunities to put Monis behind bars were missed.

Rightly, the coroner has strongly defended the need for this to have been an open and transparent inquiry, despite NSW Police Association arguments to the contrary.

Correctly, he says nothing he can say or do will ease the suffering of the bereaved families of Tori Johnson and barrister Katrina Dawson. The families have made no bones about their distress and anger at the way police responded to the siege.

However the coroner's swathe of 45 recommendations should, at the very least, ensure that NSW Police respond with world's best practice to any future terrorism event.

The acknowledgement of new Police Commissioner Mick Fuller that this needs to happen is long overdue.