The court heard how the couple, who still lived with their parents, had bought and furnished a home in Barcelona and planned to move in together after their trip to New Zealand.
Days after their funeral, friends and family planted two trees on a hill where the couple used to meet.
Coroner Brandt Shortland adjourned the inquest for four weeks to consider his findings after lawyer David Grindle, representing the Spanish families, raised concerns over the maintenance record of the truck in the crash on State Highway One, near Callaghan Rd.
Mr Grindle said that, three weeks before the fatal crash another driver had reported steering issues with the truck. The coroner wanted maintenance records for the truck to see whether there was a legitimate problem or if the crash was driver error only.
Serious crash investigator Warren Bunn said the truck was inspected and the steering box removed and thoroughly examined and no mechanic faults were found that could have contributed to the crash. He concluded the truck driver lost control, crossed the centre line and was unable, under heavy braking, to bring the truck back on to the correct side of the road.
Kaipara mother Lisa Berger and her 2-year-old son were in a red double cab ute behind the campervan. She described how the truck veered into the northbound lane and she had to take evasive action by driving into the southbound lane.
The trailer jack-knifed and clipped the front of the ute, smashing off the canopy. Her son was left with a significant gash to his face and a broken cheekbone.
The truck driver, who was wearing no shoes, came and checked on her.
The coroner acknowledged it was a miracle Mrs Berger, who was 18 weeks pregnant at the time, and her son were not killed as well.
Police had done a major search for the truck driver in a bid to get him to attend the inquest but they were unable to find him.
Truck driver Ioane Etuale, of South Auckland, was charged with causing the deaths of the two tourists but escaped conviction. He pleaded not guilty to two charges of careless driving causing the deaths and was also charged with careless driving causing injury in relation to a 2-year-old boy in a ute.
The court heard while Etuale was not convicted on those charges he was found guilty of careless use of a vehicle - a truck - on February 28 this year.
It was also revealed he had numerous log book offences between 2005 and 2010 for which he had been suspended from driving and had a previous conviction for careless use of a motor vehicle causing injury in 1998.