LoL, interesting. Well, it was a positive goof-up, anyway, I would say. Worf taking command at that point isn't really meaningful at all, while Kira doing so makes for a nice moment.
It seems to lead in, accidentally, I guess, to her being left in command of the station and her promotion in the next season.
Edit: Re-reading that quote, it seems like the "goof-up" is just forgetting that Worf would technically outrank Kira on the Defiant, but from the point of view of the story, Kira is the better choice by far.