A senior psychologist at a prestigious Perth school has been fined $2000 for assaulting a 12-year-old autistic boy by throwing a cup of water at him.

But a magistrate today acquitted Agni Angelkovska, 50, of using the boy’s hands to slap himself in the face during a “protracted” struggle at Christ Church Grammar School in November 2014.

During a three-day trial earlier this month, the court was told the boy had to be carried by four staff members at the private school to a sensory room after he had a “meltdown”.

The boy, who cannot be identified for legal reasons, was placed on the floor and calmed down by staff who applied pressure with cushions and blankets.

Magistrate David Maclean found Dr Angelkovska “inflamed” the situation by making deliberately provocative comments.

They included that he would not be going into mainstream education in the senior school the following year and that the Year 12 boys would “pummel” him if his behaviour continued.

Nobody saw the alleged slap but witnesses claimed they heard slapping noises and Dr Angelkovska saying: “If you hit me, I’ll hit you twice as hard”, and “what you do to me, I’ll do to you”.

Dr Angelkovska did not dispute there was a struggle between the pair but claimed the boy struck himself by accident.

Mr Maclean found Dr Angelkovska pushed the boy onto the couch and climbed on top of him before the “protracted” and “entirely unnecessary” struggle, but said he could not find beyond a reasonable doubt that she used the boy’s hand to slap his face.

“Whatever my grave concerns might be, I simply cannot be satisfied of what occurred in the course of the struggle which was not seen by any person,” he said.

He rejected evidence given by an education consultant that she confessed to slapping the boy.

Mr Maclean, however, did find Dr Angelkovska threw a cup of water at the victim, who had earlier thrown a cup of water during his meltdown, and that she told staff in a meeting afterwards that she was using a “mirroring technique” to explain her behaviour.

After the incident, Dr Angelkovska then threatened another, non-verbal autistic student, which Mr Maclean said was demonstrative of someone who was “very angry”.

“(She had) been in a protracted struggle with (the boy) and during the course of that struggle simply lost the plot,” he said.

Mr Maclean said Dr Angelkovska had a “dominant” personality and that she “grossly exaggerated” the boy’s behaviour and put on a “contrived” performance during her interview with police 2 ½ years later.

In his sentencing submissions, defence lawyer Simon Freitag said his client’s actions were “borne out of a very difficult, long situation” and it was a “one-off”.

Mr Freitag argued for a spent conviction, saying the incident should not mark the end of her career, but Mr Maclean refused the application.

Mr Maclean said the attack was carried out by a highly experienced and qualified professional against a vulnerable child in a place he should have felt safe and protected from the “ills of the world”.

The court was told the boy had post-traumatic stress disorder and a vivid memory of Dr Angelkovska pushing him against the sofa with her on top of him and feeling like he could not breathe.

“There was simply no justification or excuse for Ms Angelkovska’s behaviour on this day,” Mr Maclean said.

Outside court, the boy’s father, who cannot be identified, said: “This has been a very difficult journey for our family”.

“We are very happy with today’s verdict and the strength of the statements made by the magistrate,” he said.

“We would like to give our sincere thanks to those members of Christ Church Grammar’s staff that had the courage of their convictions to follow through and give evidence in this case.”

The father flagged an intention to take further action against the school.

Dr Angelkovska was awarded $11,990 in costs in regard to her acquittal on one charge.