Some legal background:
- In the United States, there are several courts of appeals, called Circuit Courts. They can disagree about legal points - this is called a circuit split. One of the purposes of the Supreme Court is to resolve circuit splits.
- Sometimes, laws are ruled to be ambiguous. If so, the relevant agency regulations interpreting the law are determinative, unless the regulations are an obviously stupid interpretation. This is called Chevron deference.
One would think that disagreement between Circuits about the meaning of a law would be legally relevant evidence about whether the law was ambiguous. Instead, there appears to be a circuit split on the meaning of circuit splits.
More available here, for the amusement of those on this site who like to think meta. Also a bit of a lesson on the limits of meta-style analysis in solving actual problems.