He admits it is distressing at times to think about the “what ifs” of that shocking day and night in December, 2014, after coroner Michael Barnes released a report on Wednesday into the siege and the deaths of cafe manager Tori Johnson, barrister Katrina Dawson and gunman Man Haron Monis.

Mr Conditsis was one of four lawyers who offered to help police contact Monis during the siege, after representing him in court in the previous two years. Mr Barnes criticised police for failing to take up the offers, or change a negotiation strategy that “was not working”.

“Adequate consideration was not given to the use of third parties in an attempt to coax Monis into communicating directly with people outside the stronghold,” Mr Barnes found.

“The negotiators did not try any alternative strategies for securing Monis’ engagement with them. They simply called repeatedly in the hope that his approach would change. Negotiators failed to pursue attempts to engage with Monis because of a lack of experience in terrorist negotiations, a lack of flexibility in approach and a lack of initiative.”

Mr Conditsis said he was not aware of the siege until the early afternoon of December 15. He contacted police after 5.30pm and offered to travel to Sydney, attempt to speak to Monis or provide police with detailed information about him.

Mr Conditsis said he had persuaded Monis, after months of discussion, to plead guilty to charges after Monis wrote ugly letters to the parents of deceased Australian Iraq and Afghanistan war veterans.

“I had a professional relationship with him. I’d seen him at his most broken when he was in jail. He was blind to how his letters to those families were offensive but I was able to talk to him and get him to see it was offensive, and he should plead guilty. I thought that with that contact I might be able to assist police,” he said.

“I did not go to bed until 11.30pm and I did not receive a call from police. I woke at 4.30am on December 16 and heard and watched the news.”

Mr Barnes noted that a barrister who had represented Monis spoke to police at 2pm on December 15 offering to help contact Monis. Two solicitors who had represented Monis were at the siege and offered to help police, but their offer was not taken up.

Mr Barnes said the use of third party intermediaries in siege situations was “complex and far from risk free”, but police had relied on negotiating tactics used in domestic situations, and there was no direct contact between Monis and police at any time during the siege.

There was “no proper explanation” from police why they did not consider a third party intermediary, Mr Barnes found.

Mr Conditsis said he could accept a police decision not to take up lawyers’ offers if it was made after “careful consideration and reflection”, but that did not appear to have occurred.