Lawyers for former chauffeur Gordon Wood claim the murder case against him over the death of model Caroline Byrne was "flawed and ridiculous" and led to a miscarriage of justice.
Wood was convicted over the 1995 death of his then-girlfriend Ms Byrne after her body was found at the notorious Sydney suicide spot The Gap.
His conviction was quashed in 2012 and he is now suing the state of NSW.
Lawyers for Mr Wood on Monday opened their case in the NSW Supreme Court by heavily criticising the prosecution's reliance upon the evidence of a retired University of Sydney physicist, Associate Professor Rod Cross.
Bruce McClintock SC told the court Prof Cross had a background in plasma physics - the behaviour of high-temperature gasses - and was not qualified to speak about how a body may have left the cliff.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"The case against my client was, to put it mildly, flawed," he said.
"Some might say that, when one analyses it, it was actually ridiculous."
Mr McClintock said the jury was presented with a photograph of the cliff top said to have been taken in 1995, when it was actually taken in 2003.
This influenced theories about why the location was chosen - because it was obscured by bushes - and the area said to have been used for a "run up" in throwing Ms Byrne from the cliff.
Mr McClintock said Prof Cross admitted he knew the photograph's date was inaccurate during a Court of Criminal Appeal hearing.
"What occurred is astounding," he said.
"A man's on trial for murder - and in circumstances where it must have been obvious that the conditions of the cliff top were crucial."
Mr McClintock said Prof Cross also had a motive to see Mr Wood convicted because he was writing a book about the case.
"I'm not overstating this, it really is breathtaking," he said.
"It's breathtaking that this man could ever have been put up as some form of independent expert."
The court heard Mr Wood will be called as the first witness.
Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or Suicide Call Back Service 1300 659 467.
