Reading through the Bolton lawsuit. It says “on or around April 27,” Ellen Knight, the official reviewing Bolton’s book, had completed her review and was of the judgment that the manuscript draft "did not contain classified information." She informed NSC legal, but then...
...On May 2, Michael Ellis, the NSC senior director for intel, started another review “at the request” of Robert O’Brien, Trump's current national security adviser, who was, per lawsuit, “concerned that the manuscript still appeared to contain classified information.”
And importantly, the NSC now maintains there are instances where "several paragraphs in length" contain classified national security information. So the administration is claiming Ellen Knight — a classification specialist — missed several paragraphs of classified info.