HONG KONG, Sept 16 — A Swiss photographer who closed a door on a Chinese mainlander moments before he was assaulted during last year’s Hong Kong democracy protests should not be held responsible for the attack, his lawyers argued today.

Marc Progin, a long-time Hong Kong resident, is facing up to a year in jail for "aiding and abetting public disorder” over the incident in which JP Morgan employee Lin Nan was punched.

Footage of Progin closing the door moments before a masked man assaulted Lin went viral and caused widespread anger in mainland China.

As his trial wrapped up today both the defence and prosecution gave closing arguments in a case which has been watched closely both in mainland China and Europe.

Prosecutors said Progin, 75, deliberately shut a door leading to JP Morgan’s regional headquarters as an argument broke out between a crowd of pro-democracy supporters and Lin last October.

They argued his actions effectively enabled the assault on Lin and that Progin therefore took part in the unfolding public disorder.

Defence lawyers said Progin was simply doing his job and that he closed the door to get a better angle to capture the argument through his lens.

Defence counsel Michael Delaney said Progin had no intention to "stop, block or obstruct” Lin and that the behaviour of the crowd had nothing to do with Progin.

Lin testified that he felt frightened as the crowd shouted at him and that their "facial expression and body language were offensive”, and that he did not believe Progin was there taking photographs.

But the defence argued that Lin was not frightened and his action to stop, turn around and chant: "We are all Chinese” had "incited the mood of the crowd”.

They submitted photographs Progin took during the incident in a bid to show he was a working professional and not a member of the protest crowd.

The court heard Progin moved to Hong Kong in 1976 and forged a career as a watchmaker, frequently travelling in the region, including inside China.

After retirement he became an adventurer and photographer with multiple exhibitions, particularly on the nomadic cultures of Mongolia.

When protests swept through Hong Kong last year he often picked up his camera to document the crisis.

Lin moved to Hong Kong in 2008 and was working as a client consultant with JP Morgan at the time of the incident.

His attacker has yet to be arrested.

The trial magistrate is expected to deliver a verdict on November 13.

Hong Kong was rocked by seven months of pro-democracy protests last year, upending the business hub’s reputation for safety and stability.

Millions of residents peacefully hit the streets as anger towards Beijing’s rule exploded, with clashes between more hardcore protesters and police becoming a near daily occurrence.

Vicious street fights also routinely broke out between people on opposing sides of the political divide.

Mandarin-speaking Chinese mainlanders sometimes face hostility and abuse from Cantonese-speaking Hong Kongers, a trend that has increased as Beijing ramps up control over the financial hub.

Authorities have arrested more than 10,000 people and brought multiple prosecutions against leading pro-democracy figures.

Beijing also imposed a draconian national security law on Hong Kong in late June, describing it as a "sword” that would now hang over the heads of its critics. — AFP