CALGARY -- A police officer has told a Calgary court that a man who three of his colleagues are accused of roughing up last summer did not appear to be combative, but defence lawyers Wednesday questioned his recollection of events.

Constables James Othen, Kevin Humfrey and Michael Sandalack have all pleaded not guilty to assault causing bodily harm.

They are accused of beating up Clayton Prince after the car he was driving was pulled over on July 30, 2016. The provincial body that probes serious police actions said Prince sustained broken ribs, a collapsed lung, a facial laceration and significant bruising.

Const. D'Arcy Oakes, who said he watched events unfold from nearby, testified he heard Prince being yelled at to stop resisting arrest and to put up his hands.

Oakes described seeing the officers hit Prince with their knees and fists while he was on the ground, and said Prince had a bloodied nose and mouth when they led him to a police vehicle.

Oakes told court it did not appear Prince was resisting arrest and the officers should not have had any trouble handcuffing him.

"It appeared Mr. Prince had given up and put his hands behind his neck," said Oakes. "So it was a matter of getting his hands to his lower back where we typically handcuff at the rear."

Just as Oakes and his partner were pulling up to the scene, the camera on their vehicle's dashboard captured other officers running toward Prince and two of them hitting him while he's lying on the ground.

The video cut out suddenly. Oakes testified his adrenaline was pumping as he was trying to turn off his sirens and park the cruiser, and he hit a camera switch-off button above him by accident.

During cross-examination, defence lawyers questioned Oakes's recollection of what happened.

Humfrey's lawyer, David Butcher, said notes Oakes wrote that night don't mention the use of force.

"The purpose of your notes is that you can accurately remember what happened when you are required to give evidence about the event, often months or years later," Butcher said, to which Oakes responded, "Correct."

Butcher asked whether Oakes had failed to follow the Calgary Police Service's note-taking policy and whether his notes from that night are now unhelpful. The officer again replied that the defence lawyer was correct.

Oakes later said that according to training he'd received as a recruit, it was his understanding that he was to record only his role, not write down what other officers did.

Under cross-examination by Sandalack's lawyer, Paul Brunnen, Oakes admitted that he had in the past confused that officer with another one who was also at the scene that day.

Prince was chased by police after he ran away from a traffic stop. Charges of resisting arrest and possession of marijuana were later stayed.

The Alberta Serious Incident Response Team began investigating a month after the arrest when video from a police dashboard camera contradicted officer accounts.

Othen and Humfrey also face charges of public mischief for allegedly making false statements.

Othen faces an additional charge of assault with a weapon -- allegedly digging a key into Prince's neck.

The Crown has wrapped up its case.

Alain Hepner, Othen's lawyer, said it took longer than anticipated.

Since only one day remained in the week that had been set aside for the trial, the defence has booked four more days in November for its side.