It has been well established that a Romulan warship cannot overcome the shields of a Galaxy class star ship with a single shot. It has also been established that there is a moment of vulnerability as a Romulan ship decloaks. As the Enterprise is at red alert, with shields up and weapons ready (both are part of the "red alert" protocol), the result of a Romulan ship decloaking and firing would most likely be the destruction of the Romulan ship.
Troi goes undercover as a Romulan, presumably relying on the Universal Translator to make her language sound like theirs. It has been established that the Translator takes the voice of whoever is speaking and translates the words to the listener's language. Therefore, to the Romulans, Troi would look like a character in a poorly dubbed foreign movie, with the spoken words not matching the mouth movements, which would make the disguise impossible to keep up, but no one seems to notice. However, it is never specifically stated that Troi is using the Translator, so it could be the case that Troi speaks Romulan and is able to pass herself off as one. The Commander's suspicions about Troi's background could be based on her accent, which a non-native speaker would surely possess.
This, of course, would ignore all of the other instances across all of Star Trek in which the crew communicate readily with species never before encountered, but at least this occurrence has a plausible explanation.
This, of course, would ignore all of the other instances across all of Star Trek in which the crew communicate readily with species never before encountered, but at least this occurrence has a plausible explanation.
In "The Neutral Zone", Data explains that the Romulans had not been heard from in over fifty years, yet it is later explained that DeSeve defected to the Romulans twenty years ago.
N'Vek tells Troi of a defector named Proconsul Meret. Near the end of the story, Ensign DeSeve pronounces the name as Emret instead of Meret.