Here's what's thought to have happened: Iliopoulos, who had recently assaulted some immigrant vendors at an Athens port, got into an argument with members of Greece's far-left Syriza party, whom he called “goats” and “filthy, scurrilous” people.
The parliament's acting speaker, also a member of Syriza, asked Iliopoulos to leave. "Go away before we send you away," he said, according to the Greek Reporter. As a scrum of Golden Dawn lawmakers filed out of the room, shouting angrily on the way out, "Heil Hitler" is audible at three different moments.
It's not clear from the video if the three repetitions came from Iliopoulos or from another Golden Dawn member such as Pappas, a spokesman who was with the group at the time. But it is yet another worrying sign about the rise of extremist political movements in this troubled country. Sometimes Golden Dawn is referred to as a far-right party and, less frequently, a neo-Nazi movement. It's a fuzzy distinction, but maybe it just got a little bit less fuzzy.