A decorated senior police officer has been acquitted of domestic violence charges against his ex-partner with a magistrate expressing doubts about the woman's version of events.

Superintendent Bernard Ryan was charged with several counts of assault and intimidation after allegations were made by his former girlfriend Bianca Hudson, an unsworn civilian police employee.

On Wednesday, Downing Centre Local Court magistrate Clare Farnan found Mr Ryan not guilty of all charges.

He was facing three counts of common assault, two counts of assault occasioning bodily harm and a charge of intimidation.

She said Ms Hudson's evidence during a hearing last November had numerous inaccuracies and inconsistencies and she could not be satisfied of Mr Ryan's guilt to the criminal standard of beyond reasonable doubt.

This included Ms Hudson's claim that an argument between the pair in January 2014 at her Cronulla apartment was sparked by her seeing a news report about a motorcyclist fatality on the North Coast and her fears that the rider was her ex-husband.

Ms Farnan said there was no evidence of any fatal motorcycle accidents on the day in question, although Ms Hudson was adamant she had seen a news report.

Ms Hudson also gave accounts of incidents to other people that differed from her evidence in court, such as the unsubstantiated claim that Mr Ryan threw furniture during an argument in a hotel room.

"These are not trivial matters in my opinion and they cast doubt about Ms Hudson's accuracy and reliability," Ms Farnan said.

"In these circumstances [Mr Ryan] is entitled to the benefit of the doubt."

Mr Ryan, a decorated police officer of 27 years and Ms Hudson, a business manager, had met at work and began a relationship in August 2013 after leaving their respective spouses.

Ms Hudson claimed on one occasion in September 2015 that Mr Ryan choked her and threw her across a hotel room in Newcastle after a night out drinking.

She described him as a "raging bull" and said she felt as if she couldn't breathe. She said the following day she saw bruises on her neck and thought she looked like a "battered woman".

However, she stayed in the relationship because she was "still madly in love" with Mr Ryan.

Mr Ryan denied choking her and said she was hitting and kicking him. He said he grabbed her to defend himself.

Ms Hudson claimed that, at their shared home in Putney in November 2015, Mr Ryan pushed her against a wall, hit her with an umbrella and spat at her.

Ms Hudson described being spat on as the most "degrading thing".

However Mr Ryan said Ms Hudson hit him with the umbrella and denied spitting.

Ms Farnan said Ms Hudson and Mr Ryan accused each other of being the aggressor.

However, Mr Ryan's evidence was more detailed and extensive than Ms Hudson's, who was sometimes vague and inconsistent.

The magistrate said her decision may have been different if she was to decide on the balance of probabilities rather than beyond reasonable doubt.

"If it's reasonably possible that he is telling the truth he is entitled to be acquitted."

Mr Ryan was embraced by several supporters after the decision was handed down but declined to comment.

He is suspended on full pay.

As a detective sergeant, Mr Ryan investigated the case of Kathleen Folbigg, who was ultimately convicted of the murder of three of her babies and the manslaughter of a fourth baby between 1989 and 1999.