The court in the Dover case was persuaded by the evidence before it, which is on the net eg >here<).I would like to see your evidence, how do you know that the flagellum can evolve on a step by step basis (one mutation at the time) where each mutation is betefitial.
Or you could start with the >outline in Wikipedia<.
But as I remarked earlier, 'irreducible complexity' can never be shown to mean more than 'presently unexplained'.
And 'presently unexplained' is incapable of implying the supernatural, not least because the concept of the supernatural is incoherent when applied to reality.
And there are no extant examples of purported 'irreducible complexity' anyway.