> they can probably scrub through the data to find out whether there have been any mentions of the similar approach

They did check and it was in the trainingset but they could not confirm if it was the /cause/ of it, which is a bit of a cop out.

> They did check and it was in the trainingset

Do you have a source, especially of what was in the training data specifically?

As I mentioned, they would have to find out whether the mentioning of the approach is only present in Tristan Buckmaster's chats and not in other users', including free users', chats.