Personally I consider that the classical algorithm evolved into a higher order algorithm called a design pattern, which utilizes multiple algorithms together which itself doesn't have a bounded time but makes use of algorithms which do execute in bounded time.
It was sort of funny how Bart & Wes were trying to specialize the general semantics to fit modern practice and machine architecture so they could connect it with classical computer science. But this is basically just explaining how computer science evolved and the algorithm can be formally defined, even though we just have basic common knowledge of this if we program, but as this lecture shows, the math and science and formal explanation shows how computing can indeed be complex and its great that we can abstract away the need for knowing all this to create a massive learning curve.
@ivan_ I've understood the meaning of "crash" to be interchangeable with "fail". So things fail and don't work which implies a crash to happen and being invalid. But that is just my understanding and not his formal explanation on the subject.