Given all the circumstances, Const. Ryan Simpson acted reasonably and legally in stopping, handcuffing, searching and placing Nicholas Wright in the back of a cruiser, the officer's lawyer argued.
While the detention may not have been by the book, lawyer Alan Gold said, Simpson had no "moral culpability" in doing what he did.
"It was a highly volatile situation. Police were under enormous pressure," Gold told the tribunal.
"This was a perfectly reasonable detention. It was not an arrest. Everything (Simpson) did was necessary, lawful and perfectly reasonable."
Simpson, the first of 32 officers to face a misconduct hearing arising out of the G20, has pleaded not guilty to arresting Wright illegally. The incident on June 27, 2010 came a day after mayhem erupted in downtown Toronto when vandals mixed up with protesters went on a rampage.
The officer maintains he stopped Wright for cycling fast between lanes of traffic. He said he then noted the rider had a neck scarf and swim goggles around his neck, was wearing a backpack, and a large group of cyclists was nearby.
Wright, 31, a lawyer, initially told Simpson he was out for a ride with his girlfriend. He gave his name and address, but refused to answer any further questions.
He testified the officer told him he was under arrest for wearing a disguise, but Simpson denied that, saying the detention was only for investigative purposes.
Wright was released without charge after about 19 minutes.
In closing arguments, prosecutor Brendan Van Niejenhuis said what happened to Wright was, to all intents and purposes, an arrest in which the officer violated his rights by failing to tell him of his right to a lawyer.
"It would be reasonable for anyone to conclude, as Mr. Wright did, that he was not free to leave," Van Niejenhuis said.
Simpson, who had been instructed to arrest anyone wearing a bandana, might have been "between a rock and a hard place" but what he did was still unlawful, the prosecutor said.
To be legal, Van Niejenhuis argued, the detention had to be clearly tied to suspicion a criminal offence had been committed or was about to be committed.
"The G20 was the general criminal investigation: the violence, the mischief, the vandalism," Gold countered.
"This wasn't just a nice sunny Sunday afternoon when they were out and about."
Gold fiercely attacked Wright's credibility, accusing him of being an anti-police activist who allowed his beliefs to colour his perceptions, or simply lied outright about the events.
Among other things, Wright omitted any reference to having swim goggles on three occasions, and lied about being out with his girlfriend when he was in fact part of a large group of nearby cyclists, Gold said.
"You cannot rely on his evidence."
For his part, Van Niejenhuis said Wright had been "forthright and forthcoming," but said the legality of the arrest had nothing to do with his credibility.
Retired Ontario court judge Walter Gonet, who is hearing the case, reserved his decision until Nov. 21 or 22.