Police showed a "complete lack of judgement" over the prosecution of a learner driver who stopped past a red light at a junction, a barrister said.
Joseph Bell, 18, was having a driving lesson when he stopped over the line at a junction on the Colwick Loop Road in Nottingham on 14 December last year.
He admitted failing to comply with the red light, but Nottingham magistrates accepted special circumstances.
Mr Bell was granted an absolute discharge. Police defended the case.
The court heard Mr Bell - who was 17 at the time of the lesson - had been slowly approaching the junction in the car, with his driving instructor present and also able to take control of the vehicle.
It was caught by an automatic camera as having stopped into a red light area for 14.8 seconds, with no oncoming cars or pedestrians present.
Bruce Stuart, defending Mr Bell, said the car would not have presented a danger to other road users if there had been traffic. He said if the car had been travelling at speed this would have been recorded on the camera and any sign of danger would have seen the driving instructor moved into action.
"If there was a danger, he would have stopped the car," he said.
"This is something that learner drivers do - they make mistakes."
Mr Bell's driving instructor wrote a letter supporting his student, telling magistrates it was "a simple lapse of judgement" that can happen "on occasion" with student drivers.
In granting an absolute discharge, Mr Bell will not have any points put on to his driving licence, or have to pay costs.
Magistrate Richard Eaton said the incursion into the junction was "minimal" and would have been "nowhere near" traffic if the road had been busy.
Following the hearing, Mr Bell - who is set to take his test in the coming weeks - said he was "relieved" at being discharged.
"Those three points would have proved [to be] a lot of hassle," he said.
Gaynor Bell said she was "completely frustrated" with the police decision to back the prosecution against her son, especially as a driving instructor was in the car at the time.
"As a parent you put your trust in them - that's why you use driving schools," she said.
Mr Stuart said the case was "very unusual", adding the discharge "shows what the court thinks" of the prosecution.
"[It] shows you what overwhelmingly bad judgement the police showed in [backing] it," he said.
"It's really a wake-up call for driving instructors, because he was very lucky that he wasn't charged."
Insp Simon Allen, from Nottinghamshire Police, defended the force's actions over the case, saying there is "no mitigation for learner drivers when committing a traffic offence" and it was the job of officers "to uphold the law".
"The safety of all road users is paramount, which is why the law holds learner drivers equally accountable and they must ensure that they follow the rules of the road," he said.
"In these cases, drivers have the choice to take a ticket or to go to court as happened here."