According to The Independent Journal’s congressional reporter Joe Perticone, the man holding the camera in the video
below is a journalist. Perticone writes, “Secret Service agent choke slams reporter. ” The video doesn’t show that [updated] Videos added below appear to show the reporter intentionally bumping up against the agent and saying “f*ck you” before the agent throws him to the ground. From the ground, you can see the reporter kicking the agent from an apparent defensive position.
Nevertheless, once whatever happened between the two men is over, and both are standing, watch the reporter suddenly reach out and grab the Secret Service agent’s throat.