Gordon Wood has been acquitted over the murder of his girlfriend Caroline Byrne

Mr Wood was not present in the NSW Court of Criminal Appeal on Friday when Justices Peter McClelland, Megan Latham and Stephen Rothman overturned his murder conviction.

In 2008, Mr Wood, then 46, was found guilty of murdering 24-year-old Caroline Byrne by "spear throwing" her off a cliff at The Gap, a notorious Sydney suicide spot, late on the night of June 7, 1995.

The former chauffeur was jailed for at least 13 years after the jury rejected a claim that Ms Byrne, whose mother killed herself in 1991, had jumped off the cliff.

Days before her death, she had seen a doctor, who referred her to a psychiatrist, describing her as "very, very depressed".

But Mark Tedeschi QC, for the crown, alleged Mr Wood killed his girlfriend because she wanted to end their relationship and he feared she would reveal personal and business details about his boss, stockbroker Rene Rivkin.

Justices McClellan, Latham and Rothman heard the appeal over eight days last August and September.

The nine grounds of appeal included a submission that the scientific evidence and opinions of a crucial crown witness, Associate Professor Rod Cross, caused the trial to miscarry.

Mr Wood's barrister also argued that Mr Tedeschi had used pure speculation and emotion to get a conviction.