It’s irrelevant if it’s truly a religious belief or a dramatic presentation. We are speaking of a federal judge and the limits of his authority. The judges themselves have private lives which should be left at home when they sit on the bench. They operate within the limits of constitutional law. Nowhere in that law are judges given the power to determine what is or is not religious in nature.
Creationism is not, and never will be, science. It rejects the scientific method in favor of a particular interpretation of scripture.
Judges rule on what is religious in nature all the time, how else would they ever determine if a law is “respecting the establishment of religion” if they were somehow unable to discern what “religion” even was?