But Guy followed rules which state anyone with four or more identical traffic infringements over two years could be barred from becoming a Kiwi.
And because Macdonald paid the fines promptly, there is no way to get photographs from the speed cameras to prove he was not the person driving.
The decision meant Macdonald was stranded in New Zealand while his wife Joanne flew to the UK with a new Kiwi passport to attend a memorial service for her mother.
Joanne Macdonald and their teenage son were sworn as New Zealanders last Tuesday. Macdonald looked on, excluded from the family ceremony.
He said as part of the ceremony, Joanne Macdonald was asked if she wanted to sing the national anthem, God Defend New Zealand. In the circumstances, she said she couldn't bring herself to.
Macdonald has lived here for 15 years as a permanent resident and decided to go for citizenship when the memorial came up.
He said he had decided not to reapply for a South African passport - which would have taken too long - and he had hoped to join the rest of his extended family as an official New Zealand citizen.
"My parents both came here. They got citizenship. They are Kiwis. We buried them here."
Macdonald said his two sisters and their five children were also Kiwis, as were his cousins and uncle. "I'm the only one who was turned down."
He said he also could not understand the decision given the key role his company played in a Ministry of Education initiative to put ultra-fast broadband into the nation's schools.
He said he had been told to wait a year then apply again. By then, four of the speeding tickets would have dropped off the list.
A spokesman for the Internal Affairs Minister said Guy was satisfied he had made the right decision and Macdonald could apply again in future.
"Citizenship is a privilege, not a right, and has to be earned."