Eric Garner’s sister left a New York courtroom in tears as a video showing the 2014 arrest that led to the Staten Island man’s death was played. Garner’s mother also left in tears.

The man who took the video was testifying at a long-delayed disciplinary hearing for New York police officer Daniel Pantaleo.

Garner, 43, was the unarmed black man whom Pantaleo put in an illegal chokehold and whose pleas of “I can’t breathe” during his July 2014 arrest became a rallying cry for protesters against police brutality.

Pantaleo has been on desk duty since Garner’s death. In court his lawyer, Stuart London, said in an opening statement the officer was being made a scapegoat in a politically charged atmosphere.

London said it was a misconception that the phrase “I can’t breathe” was uttered when the officer’s hands were around Garner’s neck. He said it happened when officers were trying to handcuff Garner, who had been selling loose cigarettes.

London also said that “we know he wasn’t choked out because he is speaking”.

Pantaleo, London said, feared Garner was trying to push him towards a plate glass window.

The man who took the video, Ramsey Orta, testified from prison, where he is serving time for drug and weapon charges. During cross-examination, Orta said Pantaleo’s arm wasn’t around Garner’s neck when he said “I can’t breathe”.

Orta also backed off a claim he made to internal affairs investigators two days after Garner’s death that Pantaleo had his knee on Garner’s back for five to 10 seconds. The video showed it was not on his back.

Pantaleo could face penalties ranging from the loss of vacation days to firing. He denies wrongdoing.

A ruling last week required the police watchdog agency bringing the case to prove not only that Pantaleo violated department rules, but that his actions fit the criteria for criminal charges, which Pantaleo does not face.

In 2015, New York City agreed a $5.9m settlement with the Garner family, thereby avoiding civil litigation.

Towards the end of the first day of testimony in what is expected to be a two-week disciplinary case, the watchdog agency acting as the prosecutor called two police officials to the witness stand who were involved in an internal affairs investigation of the matter.

The men say their investigation found that Pantaleo probably violated department rules regarding a chokehold and that a request was made in January 2015 for internal disciplinary charges against him.

The police department put the disciplinary matter on hold while federal law enforcement investigated a possible civil rights case against Pantaleo.

The department decided to move forward last year. The US justice department has until July to file charges.