Snipers in the Lindt Cafe siege believed they did not have lawful authority to shoot terrorist Man Haron Monis because he did not pose immediate danger to the hostages, an inquest has found.
"That was, in my opinion, an unduly restrictive view of their powers and underestimation of the risk the hostages face," NSW Coroner Michael Barnes said on Wednesday.
"Their interpretation of the circumstances failed to have sufficient regard to Monis' possession of a shotgun and suspected IED, his threats, his claimed allegiance to Islamic State, his unwillingness to negotiate and his continuing to unlawfully deprive the hostages of their liberty."
Mr Barnes called on the minister for police to consider amendments to the terrorism police powers act to ensure police officers have sufficient legal protection to respond to terrorist incidents.
"It may be that the special powers available to police responding to terrorist incidents should include a more clearly defined right to use force," Mr Barnes said.
Soon after the December 2014 siege commenced, snipers were positioned in three locations overlooking the cafe.
While they were heavily armed, the snipers failed to fire a single shot at Monis.
"The 10 minutes that lapsed without decisive action by police was too long," Mr Barnes said.
"Tori Johnson was executed in the meantime before the decision to enter the cafe was made."
Mr Barnes said on Wednesday tactical police also threw too many devices.
He said 11 explosive devices were thrown into the cafe that produced 99 explosions "which was counter-productive".
He dismissed criticism on police for not taking a shot at Monis, concluding it was too dangerous to shoot him without risking the lives of the hostages.
"They (the snipers) could not discount the risk that any hostages who were nearby might be killed or injured if they tried to shoot him," Mr Barnes said.
"In any event, they believed they did not have the lawful justification to shoot.
"In those circumstances, the snipers should not be criticised for not taking a shot at Monis. They could not have safely resolved the siege."
Police did not try to enter the cafe until after Monis had killed cafe manager Tori Johnson.
Sydney barrister Katrina Dawson was fatally wounded by police bullet fragments as the Martin Place stand-off came to a horrific end in the early hours of December 16 after 17 hours.
Man Monis was shot by specialist police who stormed after Mr Johnson was killed.