2014 Sydney hostage crisis
After the siege began, a staged exclusion zone was established with thousands of people evacuated from nearby buildings, including from the floors above the café. The Sydney Opera House was evacuated after a suspicious package was found; however, reports were unconfirmed by police. The US Consulate General in Sydney, located in Martin Place, was also evacuated. Some Sydney schools were put in "white level lockout" due to the hostage situation, which meant that no school group was permitted to leave the school grounds.
Sydney siege inquest
Army advisors were concerned that the high velocity 5.56mm bullets could fragment and kill hostages. For close range operations like this they would have used larger but slower 9mm bullets. They complained about a lack of cooperation from the NSW Police. The army had gained substantial experience of these types of operations in Afghanistan. 
After some hours of negotiation, police withdrew their attempt to keep their actions during the siege discussed in camera. However, issues dealing with "methodology" would be secret.
Superintendent Allan Sicard said that he "was OK" with allowing Monis to speak on ABC radio in exchange for hostages early during the siege. It is unclear why this did not happen.