I wonder whether the original study was in GPT-5's training data. I asked it whether this was the case, and it denied it, but I have no idea whether that result is credible.

I was also wondering this, and in one of the footnotes they say "Given that our experiment was conducted in 2025, one might wonder whether Kansas’ updated law is reflected in GPT’s training data and thus skews its decisions. We find no evidence of such contamination." when talking about a specific updated law. But how does one have 'no evidence of such contamination' without seeing the training data?