But, according to the Crown, Const. Babak Andalib-Goortani was overwhelmed by the chaos and "lashed out" at the protester, hitting him with a baton after the man had already been wrestled to the ground.
The fate of one of two police officers criminally charged in the wake of clashes at the G20 summit in Toronto three years ago is now in the hands of a judge after both sides gave their closing arguments.
Adam Nobody, a 30-year-old stage hand, was singled out for arrest at a demonstration June 26, 2010, at the Ontario legislature and was tackled as he ran from police.
Andalib-Goortani saw four other officers struggling to restrain Nobody on the ground and the officer jabbed Nobody with his baton three times toward his thigh, his lawyer said.
He then stopped and stood up once his fellow officers managed to get Nobody into handcuffs, Harry Black said in his closing arguments, calling Andalib-Goortani's actions a "textbook example" of police training.
Andalib-Goortani has pleaded not guilty to assault with a weapon.
The officer used force, but it was not excessive or criminal, as the Crown alleges, Black said.
"In the midst of an altercation, an attempt to arrest someone, it's almost as if they are suggesting that police should stop and say, 'If I let you up will you behave yourself?'" Black said.
The city was under siege that day by a group of destructive protesters who had broken away from a peaceful march and began vandalizing Toronto's downtown core. Protesters had been hurling rocks, flammable projectiles and anything else they could find at officers, Black said.
At one point police were ordered to run away from the violent demonstrators and it was in that context that Nobody's arrest took place, Black told the court.
"There was in Toronto that day a complete breakdown of ordered society," Black said. "It shocked the conscience of the city in that it was an outbreak of brazen lawlessness, crime, disorder and violence that no one had ever seen or even imagined."
Andalib-Goortani's training had not prepared him for those conditions, and, as part of an arrest team and not the public order unit who wore so-called riot gear, he had no shield and no protective clothing beyond a helmet, Black said.
Crown Attorney Philip Perlmutter agreed that Andalib-Goortani was ill-prepared to deal with the events that day and said it left him overwhelmed, fearful and feeling helpless that he couldn't respond to pleas for help from other officers over the radio.
"His condition was compounded when he was thrust into a situation he had not been trained for," Perlmutter said. "As a result when confronted by Mr. Nobody, his feelings overtook his judgment and self-control. He lost it and lashed out."
Nobody denies resisting arrest and testified that he doesn't know why police singled him out. By his account he had spent some time observing the protest, chatting with a friend, going to buy beer and returning to make a funny poster only to be arrested.
But several police officers testified that Nobody had been inciting the crowd for hours before his arrest, taunting and swearing at police, threatening to kick their heads and urging fellow protesters not to obey police orders. He can be seen in the background of a local newscast played in court standing just a few feet away from a police line, facing the officers. Black seized on that image.
"I liken Mr. Nobody's actions in front of that police line to the actions of a field general back in the days where wars were fought between opposing lines of warriors facing each other," he said. "Mr. Nobody was like that. He was on the front line with those people urging them on."
Even the Crown conceded there is "an abundance" of evidence contradicting Nobody's version of events.
"Admittedly and candidly there is absolutely no question that you are going to have difficulty with his evidence," Perlmutter said.
After Nobody was tackled, though, he was not resisting, Perlmutter said.
The defence went through videos of Nobody's arrest frame by frame to point out slight movements they say indicate Nobody was resisting arrest and trying to get away from police.
But Perlmutter said the slow motion video offers a perspective of what happened that doesn't reflect what Andalib-Goortani would have seen and based his actions upon at the time.
"The accused has clearly attempted to reconstruct events now in a favourable light based on the video recordings and freeze frames and to justify his use of force after the fact on that basis," he said.
"Even assuming the images confirm his version of the facts they were unobservable to him when they occurred."
Earlier in the trial court was shown a photo of three bruises on Nobody's right side. He alleges those bruises were caused by the jabs from Andalib-Goortani's baton.
The defence called a top forensic pathologist to testify that it was unlikely those bruises came from a baton. More likely, he said, they were caused by kicks.