John was 60 years old and had been a physical education teacher for 35 years.
In 2014, while he was acting principal of his southern suburbs primary school, an allegation was made that John had touched a student inappropriately.
The principal told John a student had accused him of hugging her and patting her on the backside.
Then that allegation was dropped and a new allegation was made.
This time it was alleged that John had touched the child's lower back.
Then that allegation was changed.
This time it was alleged that John had touched the child's chest as he leant over her to sign her work.
John was stood down from his job and gagged from speaking to colleagues and parents and barred from going on or near the primary school grounds.
It was difficult - he lived just down the street.
The process made him a pariah in his local community.
In the supermarket, older kids would call out "there goes (John) the pa-dophile".
If he came across parents while walking his dog, some would do "everything bar spit in my face".
Six months passed before John was interviewed by police.
That was when he learned the basic details of the allegation : who the child was, and when and where the incident supposedly happened.
The police quickly dropped their investigation.
They did not lay charges.
A few months later John was interviewed by a former police officer in the Education Department's disciplinary unit.
Almost a year later, near the end of the 2015-2016 summer holidays John received a "cold" letter from Education Department chief executive Tony Harrison.
The letter acknowledged the "extremely difficult and lengthy process for you and your family" and advised John that it had been found that "on the balance of probabilities" there was "insufficient evidence" against him.
There was no apology, not even a proper exoneration.
Tony Harrison's letter ordered John back to work for the start of the 2016 school year.
John had been sidelined for more than 600 days while he was being investigated.
The months of isolation had ruined John's mental health.
He had developed severe anxiety and was diagnosed with post traumatic stress disorder.
"All through the process they make you feel as guilty as hell," he says.
John was barely 10m inside the school gates when he felt the panic rising within him.
He knew he wasn't ready to teach again.
John's career was in tatters.
He is now on sick leave and he has taken Long Service leave to give himself time to recover.
He hopes to be well enough to teach again in 2017.
After his experience, John says he would never encourage young men to take up teaching.
If he is well enough to return to the classroom in 2017, he will refuse to teach Physical Education because it involves direct contact with students.
He will avoid leaving his desk in the classroom.
"It goes from zero to psycho in an instant," John said.
"I am so p-ssed off because of the indignity of what I had to go through.
"I would discourage any young man from going into teaching."
The South Australian Education Department finalised 80 disciplinary investigations during 2015.
John and the Australian Education Union argue that many of these investigations should have been resolved quickly at the school level.
John estimates that his case must have cost taxpayers $250,000.
The South Australian Education Department must be wasting millions of dollars of taxpayers' money each year investigation frivolous or vexatious allegations.