For the first time in a Brampton courtroom Tuesday, a Toronto police officer provided an eyewitness account of the moment Chadd Facey was tackled to the ground after selling a fake Apple watch to two off-duty police officers, hours before his death in 2021.

Const. Gurmakh Benning, who has worked with Toronto police for nine years, testified that he saw Const. Calvin Au take Facey to the ground near a ravine in Brampton, moments after Benning had gotten his money back for the fake watch Facey had just sold him.

"Almost instantaneously, Calvin took him down," Benning told the court.

Au faces a charge of assault causing bodily harm at the judge-alone trial, which arose after what court has heard was a "Kijiji deal gone bad" on April 26 of that year.

Facey died in hospital later that day, but an agreed statement of facts in the case states the Crown "is not in a position to allege that Facey's death was caused by the interaction with Au."

Au has pleaded not guilty.

Benning testified that he and Au, who were work friends, met up with Facey that day in the parking lot of Beryl Ford Public School after he had arranged to buy a sixth-generation Apple watch from the 19-year-old Brampton man on Kijiji. Au, he said, came along because he is more tech savvy and owned an Apple watch of his own.

Shortly after completing the deal for $400 and opening the sealed box, Au noticed the watch was fake, Benning said.

"I [felt] like I got ripped off and I … wanted my money back," Benning testified.

Facey, court heard, had already taken off down Franktown Drive at the time, but the two men managed to catch up to him in Benning's car. That's when Facey rolled down his window and said he wanted his money back.

"Then he bolts across the front of my car, down into the ravine," Benning said.

Au, Benning testified, got out of the car and ran down into the ravine to give chase. Benning, meanwhile, pulled a U-turn, and later saw Facey coming up a nearby trail.

Benning got out of the car while it was still running, ran over and caught up to Facey, he said.

"I told him to give me my money back," he testified. "I reached for the money in his hand, and I took it."

Facey didn't resist and Benning thought the chase was over with — but that's when, court heard, Au caught up and tackled him.

Benning said he followed the pair down to the ground as well, based on instinct.

"And then I basically went down, and got up, and then I was about to call 911, and then I observed a female in an SUV, and she stopped by and asked if everything was OK."

A recording of that 911 call was played in court, with the Toronto police officer testifying that it was made as he and Au were getting back in his car.

"At that point [Facey was] already getting up as we're in the vehicle," Benning said.

Benning told the operator that he was robbed, and in the background of the call, Au can be heard saying "go, go, go" as the two drove away.

Benning told the dispatcher that he wasn't hurt, and also that police weren't needed at the scene.

"We don't mind meeting officers if they like, but we just want to get out of the area," he said on the call.

Au, who had been with Toronto police for eight and a half years before he was suspended in the wake of Facey's death, was initially facing charges of both manslaughter and aggravated assault linked to Facey's death.

A Ministry of the Attorney General spokesperson confirmed to CBC News that the trial is now proceeding solely on an assault causing bodily harm charge, which, according to The Toronto Star, was prompted by a change in forensic pathology witnesses.

The trial continues Wednesday.