IMHO, they call that a flash crash because by 1962 standards, it was. But I'd say there was some significant qualitative differences. The Wikipedia article on the 2010 crash [1], for instance, talks about things like "At 2:45:28 pm, trading on the E-Mini was paused for five seconds when the Chicago Mercantile Exchange ('CME') Stop Logic Functionality was triggered in order to prevent a cascade of further price declines." Emphasis mine. Markets have always been able to crash quickly, but without computers you're not going to get phrases like "paused for five seconds" to mean anything.
[1]: http://en.wikipedia.org/wiki/2010_Flash_Crash