“It is regrettable that the defendant adopted an unlawful way to respond to injustice, squandering his promising future and losing freedom,” Lee told the court.

Ho was seen to throw objects at the white-shirted group and to open an umbrella to shield himself and some people dressed in black- the colour favoured by anti-government protesters- in the station and on nearby Long Wo Road at around midnight.

The court earlier rejected Ho’s claims that he went to the station out of “being curious” and that his actions there were in self-defence and an attempt to prevent criminal activity.

“The degree of violence, use of weapons, and premeditation of the white-clothed people are all more serious than those on the non-white-clothed side,” Lee said.

“The non-white-clad individuals, however, fought back with force, responding to violence with violence. They also have to pay a price.”

The sentence was the first to be handed down in a case not linked to the white-clad group, who stormed the MTR station and attacked protesters as they returned from a demonstration on Hong Kong Island on July 21, 2019. Ordinary commuters were also caught up in violence.

Ex-lawmaker went to scene of mob attack out of concern, Hong Kong court hears

Lee said the sentencing standard for Ho was between three and 3½ years in prison, because “the scale of the riot and the circumstances of the crime at the stage the defendant was involved are assessed as low”.

Because of the small degree of violence used by Ho during the confrontation – the objects he threw were not lethal – Lee said he had at first decided on a three-year sentence.

Lee, however, added that factors such as the defendant’s good background and the delay in prosecution mentioned in the pleas in mitigation, led him to cut the sentence by three months.

It took almost two years from the time Ho was first arrested to when he was charged.

“The defendant in this case is a young professional,” Lee said. “He was blinded when he saw the scene of white-clad people attacking people in the compartments.”

Hong Kong police told of risk at MTR station 2 days before 2019 violence: witness

Lee said Ho’s judgment was “clouded with anger” and that he believed the defendant had reflected on and learned from the experience.

Another case linked to the mob attack is also being heard in the District Court.

The trial involves former lawmaker Lam Cheuk-ting and six others – Yu Ka-ho, Jason Chan Wing-hei, Yip Kam-sing, Kwong Ho-lam, Wan Chung-ming and Marco Yeung Long.

The seven, who were also not part of the white-clad group, have been charged with a joint count of rioting.

All have pleaded not guilty.