Detective James Middleton said Richardson, a local lawyer who had been the subject of a previous complaint for running at night without reflective clothing, was wearing a fluorescent top with a strip of reflectors on the back when the crash occurred.
The Road Code says those jogging at night should wear light or white coloured clothing, at a minimum.
"It's open to interpretation and that could be one of the factors in the decision not to charge," Middleton said. "But [his clothing] doesn't make the grade, in my opinion. He believed it did."
The burden of proof was high in such a case, he said.
"For example, you have to prove he was so reckless in his actions that it amounted to an unlawful killing. That's a very, very high standard."
Many people told police after the crash they had seen Richardson, or someone matching his description, jogging at night without reflective clothing.
He would not say if there had been any complaints since MacRae's death, but said Richardson now wore a retro-reflective vest when running.
It was "desperately sad", Middleton said.
"He was a hard-working, decent man who has been tragically killed."
For Sophie, one of the most upsetting moments was receiving a letter from Richardson after her husband's death in which he denied any responsibility and did not apologise.
"It was just on a scungy piece of paper.
"A police officer gave it to us. He said he didn't want to but he was obliged to. I feel like [Richardson] hasn't taken into account what a good man Mac was. I think, 'is this what he was worth'?"
The Herald on Sunday tried to speak to Richardson before being contacted by his secretary who asked that we "stop calling him because he has no comment to make".
Richardson previously told the Dominion Post that MacRae drove past him "as if nothing was wrong" before crashing.
Sophie said the death of her husband, a former social worker and preacher, had "blown our world apart".
With their eight grand-children, Sophie had an unveiling at his graveside last week. "They loved him so much, they were just sobbing.
"He was just a good, honest, ordinary man."
If one lesson was to be learned from her husband's death it was that joggers must make sure they could be seen at all times.
"Everybody's got to share the road."
Middleton said the case had raised "important issues" over the standards in the Road Code for pedestrians and joggers, which he hoped would be covered by the inquest in November. "Joggers and pedestrians have to appreciate the risk they pose is not only to themselves, but also to other road users, including those in vehicles."
New Zealand Transport Agency spokesman Andy Knackstedt said if people must run or walk on the roadside they should keep as far to the side as possible and make themselves visible by wearing reflective clothing and shoes and using reflectors or lights.
More than 400 pedestrians had died in road crashes in the past 10 years, but figures were not readily available on the number of motorists killed or injured as a result of swerving to avoid pedestrians on the road.
