Lloyd Rayney's defence barrister David Edwardson has attacked the prosecution's claim that liquidambar seed pods were found in Corryn Rayney's hair.
And the WA Supreme Court trial heard that a third seed pod in Mrs Rayney's body bag was not discovered until two months after her post-mortem examination.
The question of the seed pods are key to the prosecution's case because they potentially link Mrs Rayney to her Como home, where they have a liquidambar tree.
Having spent much of the day cross-examining Sergeant Siobhan O'Loughlin, one of the police officers who helped in the post-mortem, Mr Edwardson this afternoon signalled the defence did not accept the forensic evidence relating to the pods.
Earlier Sgt O'Loughlin had described to the court watching two seed pods being removed from Mrs Rayney's hair.
"I suggest… these pods were not removed from the hair as you describe to this court," Mr Edwardson said.
"I suggest to you that the pods were not removed from the hair and that's the reason why we do not have any photos of the pods in the hair."
Sgt O'Loughlin did not agree. She said she was standing beside the doctor when he "had his hands in amongst the hair and round the scalp of the head and was prising the seed pods out".
The seed pods were photographed once they had been removed from the hair but not in situ. Asked why not Sgt O'Loughlin said there was "no necessity".
The court was told last week there was only one liquidambar tree in Kings Park, which is some distance from Mrs Rayney's grave. However, they are common in many of the nearby suburbs.
Justice Brian Martin questioned Sgt O'Loughlin closely about whether there had been a delay in photographing the seed pods, in particular whether the pods had been found before or after Mrs Rayney's body was moved from lying on her front to her back.