[nchlswu]

I find the parent's quote misleading without the context.

"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