There is a longer video clip on the web (I have the clip -- lost where it is on YouTube) where Stephen elaborates on this idea.
I thought that the Nova was pretty good. They could have pointed out the nature of the problem better if they had presented the fact that Newtonian Mechanics turns chaotic when predicting the orbits in the solar system.(Discovered/proven by Poincaré in the early 1900s) I have no idea whether the solar system really is chaotic, or whether just the model is, but this is really the point. Physics pretty much studies the 'simple' stuff. When it comes to fluid dynamics, or biological systems, then an engineering mindset has to take over, with rules of thumb, 'close enough' approximations, and a constricted domain of applicability.