Just yesterday Iain said so during the seminar in Berlin. I've heard him say it at other seminars, right before he had us practicing flow drills. :-)
Now I've just found a nice example of how a nice flow is not the perfect thing to achieve in a real self defense situation
The cop (security guard, whatever) connects two dozen times or so, not a single decisive technique among them. If the other guy suddenly gets a beer bottle or something from somewhere, or his friend turns up from behind, then the nice flow is coming to a very sudden stop.
They almost look like two guys doing a well rehearsed drill they've practiced very well, with one guy acting as the clumsy untrained attacker. The other guy - the uniformed one - clearly is trained - see him blocking the first wild swing - but doesn't do damage. Too much time in the gym/dojo/sparring with good friends?
That's how I see this. I may be wrong, though, I'm no expert on street fights. What do those who are think about it, i wonder?