He denied grabbing the boy by the neck and asking: "Are you deaf?"
Police became involved after the boy returned to his mother that night.
Defence counsel Peter Coles said in his closing address it was an issue of credibility and whether the jury accepted what the boy had said or what the accused man said.
New Zealand Police Association president Greg O'Connor, who was not at the trial, said: "Anyone who believes that police officers are treated any less than anyone else in these circumstances need only look at this case."
If anything, the scrutiny on officers facing such allegations was even greater, Mr O'Connor said.
It was a case of "if in doubt put it before the court".
"The reason there is no conviction is usually because there has been very little evidence," he added.