Yep, the final man in the above video, as the BBC reporter asking the questions realizes a split second too late, isn't your ordinary man on the street—he's Henry Winkler, aka the Fonz from Happy Days (or, forever in my mind, Barry Zuckerkorn from Arrested Development).
As the man holding the mic has since explained, the whole thing was complete happenstance. "He looked a promising interviewee so I lunged forward, began my spiel and immediately realised I was addressing no less a figure than the Fonz," wrote BBC deputy political editor James Landale (British spelling his), adding that he then immediately became a "gabbling, star-struck idiot" around the American TV icon. (The BBC has the complete footage up here.) Not all was lost, however. Turns out that Winkler did have an opinion on the issue of the day in London, which was a debate over plans to expand Heathrow airport. The Fonz is for it.
Landale says his only regret was his final, parting question. "I asked if he was relaxed about the plans," the BBC journalist writes. "When of course I should have asked if he was cool about them. Perhaps while giving an interrogatory thumbs up."