On first viewing, I rated this 8/10, and it's not hard to see why: the acting keeps us involved, even when the actual plotting sorta skates us past some dodgy moments. Particularly noteworthy are Nana and Rene in the final scene. The rest, however, doesn't really hold together, and the reason is typical DS9 -- and for that matter, TV mysteries in general.
You see: like all murder mysteries, the plot turns on psychology, to untangle truth from lies. This is complicated by involving a regular cast member, where a guest role would not require continuity with past and future episodes. So the only way to really enjoy this episode is simply to accept it without critical thinking (not what we come to Star Trek for), and then we find an episode which aims to be important in the development of two main characters, and sorta fluffs it.
On the plus side, they do a pretty good job of balancing comedy and drama (e.g., Quark and Nog's scenes), and Odo stopping mid-exit to turn around and deliver a damning accusation -- that's straight-up stolen from Columbo. Even the opening camera shot tells us this will be a TV detective mystery. So there's still stuff to like; you just can't think too much about it.