Reekers' lawyer Howard Lawry told the court it appeared the sentencing judge placed emphasis on a stab wound to Ms Jamieson's neck but no mention of it was made in the post- mortem examination.
He also addressed the disposal of Ms Jamieson's body.
"He, at the time, was not thinking rationally as one might expect because the body was behind the place where he worked."
Mr Lawry said Reekers knew Ms Jamieson through a man he believed to be her partner.
"His explanation was that it was an argument over money, that was fuelled by methamphetamine."
He said the judge also should have taken into account Reeker's age and ill health that included emphysema and hepatitis.
He said his previous convictions, including one of rape in 1978, came more than 30 years before he was charged with murder.
Crown prosecutor Aaron Perkins said the sentencing judge described the 1978 conviction as being "not much better than animal-like".
Reekers could be seen mouthing words on the screen as Mr Perkins outlined his opposition to the appeal.
"To use a knife to rape a woman then subsequently to kill a woman using a knife is the clearest evidence that this man is a danger to women."
Mr Perkins said only Reekers would know what happened to Ms Jamieson and on what day.
"But enough is known, in the Crown's submission, that the level of seriousness justifies a term of 15 years."
He also addressed the contentious neck wound and said pathologists regard areas of severe decomposition as being "an indicator of an injury".
Mr Perkins said police also had evidence of an alleged confession from Reekers which included the neck injury and that the sentencing judge had noted Reekers had no memory of causing the neck wound.
The justices reserved their decision.
