If Susan Rohde's full weight had been suspended by a single cord of the curling iron from the bathroom door at Spier hotel, the cord would have failed, the Western Cape High Court heard on Tuesday.
Head of the mechanical and metallurgical engineering subsection of the SAPS, Colonel Daniel Poolman, reiterated during cross-examination that he did a number of tensile force tests to determine whether the electrical cable found around Susan's neck was used to hang her.
She was found hanging from a hook on the back of a bathroom door at the Spier Wine Estate on July 24, 2016.
She and her husband, Jason Rohde, had been attending a Sotheby's conference at the wine estate at the time of her death.
Jason has pleaded not guilty to charges of murder and defeating the ends of justice for staging her suicide.
Poolman told Advocate Graham van der Spuy, for the defence, that his tests revealed a single cord would have failed with a weight of more than 40kg, while a double cord would have held around 77kg.
Partial hanging also possible
"If the full weight of the deceased had been suspended with a single cord, the cord would have failed?" Van der Spuy asked Poolman.
Poolman replied: "That is correct, my lady".
Van der Spuy said it could have also been a case of a partial hanging where a body part touched the ground.
Poolman said he was not in a position to comment on what force would have been involved in that situation.
Van der Spuy referred to a crack on the side of the bathroom door, which was lying on the floor in court.
He said his experts believed evidence was irretrievably lost because the door had been replaced and they could not do certain experiments.
Inconsistencies over ligature marks
He was asked what he thought might have caused the crack in the door.
Poolman said the crack ran through the locking mechanism of the door and looked "like someone tried to open the door with force from the outside".
The defence lawyer asked if a downward force applied to the left hand hook of the door could have caused the crack.
He replied that it was "highly unlikely" but could not completely exclude that possibility.
Poolman previously testified that the ligature marks around Susan's neck were not consistent with the position in which her body was found.
Addressing the defence's concerns that he was not a forensic pathology expert, he said that he nonetheless had experience in dealing with damage to dead bodies and reconstructing how that may have been inflicted.
Two case numbers
The court also heard evidence from Captain Meyer September, who attended the scene on July 24, 2016.
He saw Susan's body in a white gown, blue marks on her thighs and body, a white tissue with red stains nearby, a bottle of red wine on a dresser and a black electrical cord hanging behind the door.
The defence took him to task during his testimony over two different case numbers on official documents.
Van der Spuy said chances were extremely high that the police officer was not telling the truth because there was evidence that the first case number only became available the night of July 24, 2016.
September said it would not have been possible to remove the body from the crime scene during the day without that case number.
It was also possible the system could have been faulty that day or that there were too many dockets and the night shift team recorded the cases on the system.
He was asked to bring the case number book with him to court at a later stage.
The trial continues.