Possibly. Or a writer adding flourish to an act of intuition and judgement. And the evidence does seem very very strong. Guess this would be a true positive case of confirmation bias?
"Just the first pictures were enough for her to conclude that the two paintings had been produced in tandem. After that, it was just a question of watching the evidence pile up." is a quote that seems more appropriate to me.
Yes, confirmation bias still applies, but there's no evidence in the article that suggests a hypothesis to her work was established before she did took the first set of infrared images