Interesting, I never got that far in the weeds. That dude fucked up for sure but seems very unlikely that would be a crime. Possibly a violation of FBI procedure, but that would be a hard to indict on.
For those that didn't get down to pg. 247. They cover email and IM exchanges between FBI agents, an FBI lawyer, and a rep from an unnamed agency, probably CIA. The FBI lawyer asks the other agency if Page was a source because they would need to include that in the FISA application. The other agency says they sent stuff about Page to them already and that he was likely a "digraph", meaning that he had interacted with the other agencies source but was not a source himself but he could be a sub-source, a source to the source. The FBI attorney eventually forwards an email exchange that includes the original email and he inserts after "digraph" - "Not a source" . The FBI agents use that as reasoning not to include that Page was a source/sub-source in a footnote in the FISA. So the crime would be the lawyer inserting his own color on the forwarded email without letting the recipient know it was his own commentary. The commentary wasn't necessarily incorrect either, as Paige was not a source to the other agency, rather a source to their source. Any Shaggy lawyers want to weigh in on this.
Thank you for pointing out the page Anastasis, much appreciated.