The prosecutor is not supposed to be disclosing information from the grand jury, and then spends a shockingly long signal thread talking on record with a journalist that constantly implicitly discusses/confirms information they aren't supposed to be talking about at all.
It doesn't reach the same level as the Hegseth Signal leak, but it's really bizarre stuff.
A lot like Signalgate, it's the fact of the messages as much as (if not more) than the messages themselves that matter. It demonstrates unprofessional behavior. In Signalgate, discussing what should have been classified details in an inappropriate forum and without ensuring only authorized people were present (still wrong to use Signal, but at least not broadcast to a journalist). In this case, just everything about it is unprofessional. Reaching out to a reporter who highlighted details from other reports asking her to correct details but not saying what should be corrected. None of it is professional and the "it was all off the record" at the end is a comical display of incompetence. This is sitcom stuff, but real life.
I don't think these messages are all that unusual. Well usually they have the sense to go off the record at he beginning instead of the end. But off the record complaints about reporting doesn't seem out of the ordinary.
It is not illegal for witnesses to disclose things from their own testimony. But in this conversation, Halligan is directly commenting on things disclosed by other parties thus making indirect disclosures of her own by implication.
It's incredibly risky ground to be treading, that she is doing for no apparent reason, having reached out to a reporter who wasn't even actively reporting on the case. It's pretty wtf.