That was what I thought originally, but wasn't the chicane already bricked in by '55? I had some other doubts, but there are so few pictures from that period.
He also says "What were you doing at Fordwater corner?" Later there is some footage of the Mille Miglia (sorry, "Firenze-Locarno race" ). When the fisticuffs start it's a good job they weren't wearing full-face helmets in those days!