I can imagine a researcher thinking "I should cite this in my paper. I'll cut-and-paste the text into my notes." But then later they don't recognize in their

I can imagine a researcher thinking "I should cite this in my paper. I'll cut-and-paste the text into my notes." But then later they don't recognize in their notes which text is theirs and which was cut-and-pasted. That's still "plagiarism" -- but there are cases where it can be 100% unintentional. This is all kind of beside the point, though. How you feel about this pretty much comes down to whether you support or don't support Ackman's crusade against university presidents over things that are entirely unrelated to plagiarism.