Mr Jensen confronted the man and herded him into the counter area, when he turned to see another member of the group pointing a shotgun at his head.
"That's when I just stopped dead in my tracks and thought, 'that's the end of the road, I'm not moving'," he earlier told the Herald.
The shotgun used in the robberies was later found in the same area.
Between July 17 and July 24, 2009, a white Nissan Legume worth $15,000 was stolen from an address in South Auckland.
It was found in Mark Rd, Te Puke, with some items belonging to the owner of the stolen Skyline inside it.
Yesterday's sentencing came after an 11-member jury found Galvin-Taikato guilty following a week-long trial in July, when all charges against his co-accused, Harley Adlam, 22, were dropped.
Galvin-Taikato, who has been held in custody since his arrest more than two years ago, received eight years' imprisonment for each of the two charges of aggravated robbery and a year's imprisonment for a charge of unlawfully taking a motor vehicle, to be served concurrently.
His lawyer, John Bergseng, made a plea for a lesser sentence on the grounds that Galvin-Taikato was 17 at the time and was the youngest of the group, and that the two years he had spent in remand had allowed him to "look carefully" at his lifestyle.
Mr Bergseng said afterwards that the eight-year term was within the range expected as it matched the terms that Haere Tawhiti Rex Maney, of Rotorua, and Rehua Rakapa Karika Ferris, of Manukau, were handed in October 2009 in relation to the robberies.
"Judge McGuire had really set the benchmark, and there would be no reason for the court to depart from that starting point."