The jury which convicted Robert Xie of bludgeoning five relatives to death was not warned about the possible conduct of innocent people, his appeal has been told.
He suffered a miscarriage of justice resulting from the direction given by the trial judge to the jury in relation to Xie's alleged consciousness of guilt, his barrister Belinda Rigg SC said on Tuesday.
After four trials, the former ear, nose and throat surgeon was found guilty in 2017 of murdering three adults and two children in the bedrooms of their Sydney home in the early hours of July 18, 2009.
Xie's newsagent brother-in-law Min Lin, 45, his wife Lily Lin, 43, the couple's sons Henry, 12, and nine-year-old Terry, and Lily's 39-year-old sister, Irene, suffered horrific head injuries when they were attacked with what the Crown contended to be a hammer like object attached to a rope.
The now 56-year-old Xie is behind bars for the rest of his life and is appealing his convictions on seven grounds in the NSW Court of Criminal Appeal.
Ms Rigg on Tuesday said in her summing up the trial judge referred to aspects of Xie's conduct and words that the Crown relied on to show he was aware of his own guilt.
One act involved the destruction of shoe boxes in May 2010 after he was told police thought the murderer wore a particular type of shoe.
Another involved his open mindedness to discuss "plan B" with Witness A, a prison informant, for dealing with the charges including framing an innocent person.
But Ms Rigg said at no stage did the judge warn the jury there may be many reasons why an innocent man, in Xie's position, may have destroyed the shoeboxes or discussed plan B with Witness A.
They included fear of an unjust accusation or to avoid an unjust conviction.
"It is submitted that the conduct relied upon required a very specific warning about the possible behaviour of innocent people and this did not occur," she said.
Rather than just repeating the defence case to the jury, a judicial warning was required, Ms Rigg said.
The Crown is expected to make submissions on Wednesday.