They even claim they do just that:
Natural structures will be found that are irreducibly complex, and contain parts in intricate patterns.
Only two things wrong with this prediction.
1. It is not a necessary consequence of their theory. God could have chosen to create things that were not like that. Compare to the nested hierarchy predicted by evolution. This must be true, if evolution is true.
This is vital to a prediction because it gives falsifiability. Evolution would be falsified if there was no nested hierarchy. ID would not be falsified if irreducibly complex is never found.
2. It is perfectly compatible with evolution.
By experimentally removing or breaking parts in a system, then testing for functtionality without those parts, we can determine whether the system is irreducibly complex.
This is the kicker. ID is not science because they have never done this.