You watched the irrelevant (to this discussion) part of the video. Did you not see this? "You can start about 37 minutes into it if you want to skip much of the Dover school board antics that led up to the lawsuit and get to the trial, the testimony of ID people and the prosecution's experts, and the judge's ruling."
You pay a price for your inattention. Go back to video and begin where you left off.
Or, try this written transcript of the video:
NOVA | Transcripts | Judgment Day: Intelligent Design on Trial | PBS If you go that route - text rather than speech and video - please be thorough and attentive. You will find this there. It's in the video as well, probably past the point where you ended watching it:
KENNETH R. MILLER:
As an example of what irreducible complexity means, advocates of intelligent design like to point to a very common machine: the mousetrap. And the mousetrap is composed of five parts. It has a base plate, the catch, a spring, a little hammer that actually does the dirty work, and a bait holder.
The mousetrap will not work if any one of these five parts are taken away. That's absolutely true. But remember the key notion of irreducible complexity, and that is that this whole machine is completely useless until all the parts are in place. Well, that, that turns out not to be true.
And I'll give you an example. What I have right here is a mousetrap from which I've removed two of the five parts. I still have the base plate, the spring, and the hammer. Now you can't catch any mice with this, so it's not a very good mousetrap. But it turns out that, despite the missing parts, it makes a perfectly good, if somewhat inelegant, tie clip.
And when we look at the favorite examples for irreducible complexity, and the bacterial flagellum is a perfect example, we find the molecular equivalent of my tie clip, which is we see parts of the machine missing—two, three, four, maybe even 20—parts, but still fulfilling a perfectly good purpose that could be favored by evolution. And that's why the irreducible complexity argument falls apart.