Smith had not only abused the boy's trust but that of his family. His parents felt guilty because they did not realise what had been happening to their son. And a clinical psychologist reported the offending continued to have a significant effect on the now-teenage boy who had developed severe anxiety, obsessive compulsive behaviours, difficulties with confidence and decision-making, problems with his schoolwork and difficulties with trusting men.
He would have expected some "expression of outrage" from Smith when he was confronted with the reality that the boy had disclosed, the judge said.
"But there was none of that," he told the defendant.
Smith appeared to have cultivated his friendship with the boy and had taken advantage of the boy's particular hobby interest. The offending spanned the period from February 2009 to April last year, when the boy was aged between 10 and 13 and reflected sexual conduct by Smith "over a significant time", the judge said.
At trial, the boy presented as a hesitant and reluctant witness, "embarrassed and overwhelmed" at having to give evidence. There was no motive for him to have made up allegations against the defendant, Judge Macdonald said. And he sensed that, right to the end, the boy was accepting some sort of blame.
"There was no need to," the judge said.
He told Smith the aggravating features of the offending were its scale, the length of time involved, the abuse of trust of the boy and his family, the boy's vulnerability because of his age, the premeditation and the significant grooming involved, the ongoing problems caused to the victim and the impact on his parents.
The only thing in Smith's favour was his previous good record and the fact he had made "a significant contribution" to the scouting movement.
"Nobody would have suspected you were doing what you did to the boy," Judge Macdonald told Smith.
He agreed with Crown counsel Craig Power the appropriate starting point for sentence was eight and a-half years. He also agreed with defence counsel John Westgate the defendant was entitled to credit for his previous good character.
Mr Westgate said Smith maintained his innocence, although he was aware of what that meant "further down the track".
Judge Macdonald allowed Smith a 12-month deduction for the mitigating matters and sentenced him to seven and a-half years jail on the three sexual violation charges and five years' jail for sexual conduct with a young person, all terms to run concurrently.
Smith has already been given a warning under the "three strikes" legislation.