But after declining his right to talk to a lawyer, and after the 10 minutes had begun for him to consider a blood test, Mead asked to speak to his superior.
Thorn asked his own supervisor if this was allowed and was told it was. So Mead went outside and made the phone call.
"On this occasion I think beyond reasonable doubt the 10-minute period being uninterrupted has not been established and accordingly I dismiss the charge," Judge Hubble said.
Thorn told the court he pulled Mead over at 11.24pm.
He failed the roadside test and was taken into the booze bus to undergo an evidential breath test.
It was his normal practice that when a question was asked during the 10-minute period, he would restart the 10 minutes.
Police bosses were stunned by the judgment. The head of the Harbour Bridge Traffic Alcohol Group, Grant Miller, said he was "a bit struck back".
"Nothing unusual happened that night," he said. "That 10 minute period is for people to do with as they wish." Sometimes they phoned people.
Police prosecutor Ian McMeeking said Thorn "did his job 100 per cent properly".
Mead, who lives in Hillsborough, declined to comment.
At the time he was stationed at Howick but was subsequently put on restricted duties at the Counties Manukau police district headquarters pending the court proceedings.
He may not be out of the woods yet though. Counties Manukau Acting District Commander Superintendent Nick Perry said Mead could face police disciplinary procedures.
"An employment inquiry is under way in respect of Detective Constable Mead's conduct on the night in question," he said. "Police take a hard line towards drink-driving and police employees are not afforded special treatment at any stage of the proceedings."
Police Association president Greg O'Connor said people should not think police had treated an officer leniently.
"Anyone who is thinking that police are looking after their own should reflect on the fact that he was in court in the first place," he said.
IT'S MERELY A MATTER OF MINUTES
Detective Constable Wayne Mead is not the only one to have got off a drink-driving charge because he was interrupted during the 10 minutes he had to consider whether he wanted a blood test.
Criminal defence barrister Karen Harding, who specialises in drink-driving cases, said the 10- minute period after a positive breath test should be a "quiet time to contemplate".
"I had a case recently where I got a client off drink-driving because he didn't get his 10 minutes because while he was being processed, and after he failed the breath test, he punched the police officer in the face," she said.
"They had to restrain and arrest him.
"He was jumped on and handcuffed so he got off because they didn't give him his 10 minutes," she said.
He was, however, convicted for assaulting a police officer.
Out of 33,110 drivers who failed drink-driving tests last year, 31,081 were convicted.
