This would that the proofs would be almost done anyway, which statistically could not be the case, or that these mathematicians were already progressing thanks to ChatGPT. Still a provenance question, but the impact of AI is unquestionable with regards to outcome.

The proofs would only need to be well on their way enough that the only thing needed to finish it were thousands of terawatthours of energy. Something which the mathematician having their work stolen does not have.