A Dutch lower court judge in Nijmegen has raised eyebrows by admitting to using ChatGPT to collect information while deciding on a case, the AD has reported.

The judge questioned the AI chatbot about solar panels and used the answer it generated in the verdict, much to the concern of tech and legal experts who say they have doubts about whether this was a responsible thing to do.

The case concerned two homeowners who were in a dispute about solar panels. One had added an extra floor to his home and the second argued this had an impact on the efficiency of his solar panels.

The judge asked ChatGPT to establish the average life span of a solar panel as part of his reasoning. “The judge estimates, partly on the basis of ChatGPT, that that the average life span of a solar panel from 2009 to be between 25 and 30 years, so for this case we have put it at 27.5 years,” the ruling states.

The judge also asked ChatGPT about the average price of electricity.

Internet experts have slammed the judge for taking the AI bot into account. “It is ridiculous,” Henk van Ess told the AD. “You have to take every AI bot with a pinch of salt.” In this case in particular, there is an added complication because experts are divided about the life span of solar panels, with some saying they last up to 40 years.

“ChatGPT has no knowledge. It is not a database,” said A1 expert Jarno Duursma. “It is a computer system that guesses the next word in a sentence, nothing more.”

A spokesman for the court said the judge had only used ChatGPT as one of several sources and the results were not the determining factor.

The use of AI in the legal system is not new and a number of Amsterdam law firms are using their own legal chatbot Harvey for internal use only, the AD said.

Dave Maasland of cyber security company Eset said that AI can be of great use to the legal system as a tool to reduce waiting times, simplify language and to offer cheaper legal help.

But it is crucial that its use and answers are checked thoroughly, he said. “We know that generative AI is still in the beginning stages and is not without its own hallucinations,” he said.