The premise seems flawed.

From the paper:

“we find that the LLM adheres to the legally correct outcome significantly more often than human judges”

That presupposes that a “legally correct” outcome exists

The Common Law, which is the foundation of federal law and the law of 49/50 states, is a “bottom up” legal system.

Legal principals flow from the specific to the general. That is, judges decided specific cases based on the merits of that individual case. General principles are derived from lots of specific examples.

This is different from the Civil Law used in most of Europe, which is top-down. Rulings in specific cases are derived from statutory principles.

In the US system, there isn’t really a “correct legal outcome”.

Common Law heavily relies on “Juris Prudence”. That is, we have a system that defers to the opinions of “important people”.

So, there isn’t a “correct” legal outcome.

Arguing that this is a Common Law matter in this scenario is funny in a wonky lawyerly kind of way.

The legal issue they were testing in this experiment is choice of law and procedure question, which is governed by a line of cases starting with Erie Railroad in which Justice Brandies famously said, "There is no federal common law."

You should read the paper because it addresses this.

A Socratic law professor will demoralize students by leading them, no matter the principle or reasoning, to a decision that stands for exactly the opposite. GPT or I can make excuses and advocate for our pet theories, but these contrary decisions exist, everywhere.

I am comforted that folks still are trying to separate right from wrong. Maybe it’s that effort and intention that is the thread of legitimacy our courts dangle from.

I don't think that common law doctrine applies here though. The facts of any particular case always apply to that specific case no matter what the system. It is the application of the law to those facts which is where they differ, and in common law systems lower courts almost never break new ground in terms of the law. Judges almost always have precedent, and following that is the "legally correct" outcome.

So judge rulings are the ground truth.

Remember the article that described LLMs as lossy compression and warned that if LLM output dominated the training set, it would lead to accumulated lossiness? Like a jpeg of a jpeg