> We’ve established that an IP address is not strong evidence for identifying an individual.
Well no, we haven't. There's one standard of evidence for conviction and another for a search warrant. You'd never get a conviction on that alone though.
> in any case, without providing evidence that the IP address is _only_ associated with the accused, and _not_ with any others with similar opportunity and motive
Because no other fired employee lives at her address? But that's not relevant because they got a warrant to search her address, not simply her person.
> I disagree with your contention that the fact that all users of the system used a shared username and password doesn’t complicate the case.
I do agree that it's not open and shut, but I don't think that the specific fact of the password being shared will complicate this case further.
Having the IP provides the linkage to her that is otherwise lacking because of the shared account.
> for example, any others with access to the shared username and password who might want to access the data for similar reasons, or wanted to frame the accused for hacking and put an end to the her very public/politicized efforts
There's even less evidence from which to come up with conspiracy theories than simply to blame the accused. Sure, it could have gone down in some complex and unlikely way, but why are we discussing zebras instead of horses?
And, any investigation of a conspiracy to frame her would necessarily start with the only clue - that the communication came from her IP.