I don't think so, Teofilo Stevenson knocked out all his opponents but two at the olympics, Ray Mercer knocked out all his olympics opponents, i read about a guy called Felix Betancourt that is supposedly the hardest puncher that cuba ever saw, Michael and Leon Spinks put some really good knockouts as amateurs, Mark Breland ko ratio was impressive and Robert Wangila put a lot of people to sleep in the olympics. But in the time with the electronic system (1992-2012), i never saw a fighter putting so much people on the canvas.
Hardly ever a ringcard girl looks like that, and they usually are in screen inbetween rounds, not during as far as I know.