Character mistake: Scully continually addresses the senior police officer as "Captain." But he wears sergeant's stripes. As a law enforcement officer continually dealing with other law enforcement officers, Scully is not likely to make this mistake. More likely a failure to match script with costume.
The Way of the Warrior (2) - S4-E2
Character mistake: During the Defiant's flight to save the Cardassian officials, Worf says something to the effect of, "I've never been aboard a Federation ship equipped with a cloak before". However, he was aboard the Enterprise during the Pegasus incident, where The Ship was temporarily equipped with a cloaking device.
Character mistake: Zordon begins to explain to the Rangers about their powers and then their Zords. At one point, he says "You need only to turn to the power of your Dino Zords." However, the subtitles get it wrong and spell it as if he's saying "Dinosaurs" instead of Dino Zords which is what he says. (00:10:38)