Barton has pleaded not guilty to charges of kidnapping, arson, wounding, aggravated robbery, possession of a knife, and carrying an imitation firearm.
His trial began in the High Court at Wellington today.
In a brief opening address to the jury of four women and eight men, defence lawyer Chris Tennet said they should pay close attention to Barton's video interview with police, in which he was left alone for a few minutes and gave a "monologue" in an "unguarded moment" which suggested the kidnapping was Samson's own venture.
Samson is the one who disabled the taxi's security camera, which was important to note, Tennet said.
A T-shirt with Barton's DNA and some of the taxi driver's blood on it was found with Samson, he said.
"The defence says the DNA doesn't strengthen the case of the Crown at all, in fact it just adds to the doubts."
Crown co-counsel Dan Moore said Barton and Samson robbed two people the day before, and this offending was not disputed.
One of the victims gave evidence this morning, saying he had only just arrived in New Zealand from India when he and a friend were robbed by the pair.
The victims were at Petone Beach taking photos when Barton and Samson approached, demanding the contents of their backpacks and threatening violence.
After a quick grapple, the victims handed over their money, bank cards, phones and wallets.
The man said one of the attackers told him he would smash his neck on a log and kill him if he didn't co-operate.
This afternoon, a doctor who was working in Wellington Hospital the day the taxi driver was brought in after his kidnapping ordeal gave evidence, saying the man had hairline fractures in four levels of vertebrae after the incident.
The doctor said the driver had bruising and swelling across much of his face, and other parts of his body, as well as a number of lacerations, and strong pain in his abdomen.
He needed physical therapy and occupational therapy in order to meet discharge requirements, she said.
