Cape Town - The State pathologist who examined Susan Rohde's body had "let himself down completely", the Western Cape High Court heard.
Her husband, former property boss Jason Rohde, is on trial for her murder, but his defence contends Susan had committed suicide.
Closing arguments were being heard in the court on Wednesday.
Rohde's attorney Graham Van Der Spuy told the court Susan had caused her own death and that Jason's version of events corroborated with all the objective facts, DNA evidence, fingerprints, telephone records and blood spatter evidence.
"The first person to examine her on the scene was State pathologist Dr Akmal Coetzee-Khan, who never mentioned an inside-out gown in his report,” Van Der Spuy said.
He said the "sinister motive suddenly flies out the window".
"Dr Coetzee-Khan let himself down completely in some ways, with serious ignorance of even the most basic forensic principles, not telling the truth and incompetently performing the inspection at the scene and the autopsy," Van Der Spuy said.
Jason Rohde stands accused of murdering his wife, Susan, in the hotel room they shared at Spier Wine Estate in Stellenbosch in July 2016, while they were attending a business function.
Susan's body was found hanging by a hairdryer cord tied to the bathroom door.
Jason insists he did not kill his wife.@MarvinCharles17