"I told him to stop," Pogan said, adding that the helmetless Long flipped him the bird from a bike with no lights.
"It was a split-second decision," Pogan said, telling a jury that he opted to tackle the biker instead of using a baton or Mace.
"There was no way I could have used any of my tools that were at my disposal," he said.
Pogan said his superiors had warned cops that participants in the monthly activist rally were "professional agitators."
"Do what you have to do to stop them," Pogan said a captain instructed the officers.
"I could have used Mace, but that would have cost the city more than $65,000," Pogan said.