They said Mash acted "contrary to all police training" with regard to pursuing fleeing vehicles and it was "simply unacceptable" to cross the centreline.
On November 8, Judge Lawrence Hinton convicted Mash and disqualified him from driving for three months. He was denied a discharge without conviction but Judge Hinton did grant him a partial disqualification under section 81 of the Land Transport Act.
Judge Hinton said he had some sympathy for Mash, who apart from the incident had an "exemplary" police record.
"There were ... explanations for your having taken the action you did, but at the end of the day my decision was, this was dangerous driving," Judge Hinton said at sentencing. "I do not overlook the fact that throughout you were acting in complete good faith in the course of your duty as a police officer."
Mash, who went on annual leave on November 11 until February, has appealed against his conviction and sentence.
"Since his conviction and sentence, the constable has been engaged in alternative duties that do not involve driving," said Waitemata road policing manager Inspector Mark Fergus.
"The fact that police charged this constable and put the matter before the courts highlights that our staff are as accountable for their actions whilst driving as any other motorist would be."