The teacher was said to have resisted officers after being told to leave his car, kicking Sergeant Chung Wang-yip in the abdomen.

He denied the assault and said he had been battered by police, who he claimed nearly threw him off the bridge after subduing him.

On June 12, Magistrate Debbie Ng Chung-yee found Yeung guilty after ruling his statements were not believable. She suggested he could have fabricated the story due to a personality disorder and might be mentally unfit to teach.

The judiciary received various complaints about Ng’s conduct during the trial, in which the magistrate remanded Yeung to Siu Lam Psychiatric Centre to see whether any underlying mental disabilities made him lie in court.

Yeung was granted bail by the High Court six days later.

A post on the judiciary’s website said the complaints largely argued that the magistrate “had acted in a biased manner, including analysis of evidence not beyond reasonable doubt, comments/rulings based on subjective views, and preconceived stance on sentence, etc”.

The judiciary has yet to reply to the allegations, citing ongoing proceedings.

Three pre-sentencing reports offered in court on Tuesday, including two compiled by psychiatrists, concluded Yeung did not suffer from any mental illnesses, though his mother had been battling depression for more than a decade.

Yeung’s father, according to the reports, suffered from chronic diabetes and was diagnosed with liver cancer two years ago. Yeung has been the family’s breadwinner since then.

Although the teacher was sacked by his school following the incident, his principal praised the former employee, describing him as “responsible, passionate and devoted wholeheartedly to teaching”, Yeung’s lawyer Joe Chan Wai-yin said in mitigation.

Chan urged the magistrate to pass a non-custodial sentence, stressing the assault was out-of-character and the officer had suffered no injury.

Ng said while she was “very sympathetic” towards Yeung’s parents, she saw no trace of remorse in the defendant, pointing out he failed to assist psychiatrists in making a complete diagnosis by explaining his “delusional thinking” in regard to the alleged assault by police.

“One [psychiatrist] report showed that the defendant did not tell doctors why he had such delusional thinking that [he believed] police attempted to throw him off a bridge” Ng said.

“The defendant did not exhibit a trace of reflection or remorse in the three reports.”

Following sentencing, Yeung’s defence counsel said outside the court that they would consider lodging an appeal against his conviction and sentence.

Yan Chai Hospital, the sponsoring body which runs Ho Sik Nam Primary School where Yeung had worked, said the teacher was dismissed in early July after he was convicted in June.

The school made the decision after thorough discussions and consideration, and had kept in close contact with the Education Bureau, it said.

The group said a teacher was liable to summary dismissal if he or she had been convicted of a criminal offence or committed a grave breach of duty under the government’s Code of Aid for schools.

“The Code of Aid did not specify suspending the decision of dismissal because of an appeal, therefore whether Mr Yeung applied for an appeal or whether his appeal succeeded, it has nothing to do with the school’s decision,” a hospital spokesman said.

The bureau had earlier told schools that if teachers were arrested over the protests, those charged with serious offences such as arson or assault and should be suspended for the sake of students’ safety.

A spokeswoman for the bureau said on Tuesday it would review a teacher’s registration if he or she was charged or convicted only after all appeal and legal procedures had ended.

Additional reporting by Chan Ho-him