^What's more, I thought Riker (who could be an ass at times) showed commendable restraint in dealing with Shelby, whose behavior crossed the line between assertiveness and insubordination more than once during that mission.
--Sran
He even gave her the promotion to first officer. She crossed a lot of appropriate lines in that episode.
Like giving orders on the bridge (minor), to taking Data and beaming off the ship without telling Riker-- or Picard (major).
Or announcing to Riker she's out for his job, what a way to start a working relationship
In the end they both came around to deeply respecting each other, which is cool, but notice that Shelby kept the promotion Riker gave her

(Riker gave up his after rescuing Picard)
Going even further in to the episode, the part where Data puts the the Borg to sleep and it exploding doesn't make sense to me.
After the Borg starts to regenerate, Shelby suddenly announces the entire ship is about to explode, which it does.
Why would it need to explode like that, just because it was regenerating.
Very convinent-- otherwise they would have to wonder what to do with a sleeping Borg ship that is still in earth orbit.