Star Trek: Deep Space Nine (1993)

The Way of the Warrior (2) - S4-E2

Revealing mistake: During the fight in Ops, the laws of physics takes a slight dive. While Worf is fighting the Klingons, he hits them with his Bat'leth or his mek'leth, and a second later they react to the hit.

Our Man Bashir - S4-E10

Revealing mistake: Lt. Commander Eddington is wearing the rank insignia of a junior grade lieutenant.

Paradise Lost (2) - S4-E12

Revealing mistake: When the Lakota opens fire on the Defiant, steam begins pouring into the Defiant bridge. The device releasing the steam is visible.

The Sons of Mogh - S4-E15

Revealing mistake: As Kurn is chastising Worf in the infirmary, the actor's prosthetic nose has become detached from the rest of the Klingon make up. You can see the nose wobbling around as he talks.

To the Death - S4-E23

Revealing mistake: As Sisko and Omet'iklan are arguing in the Mess Hall, the dead Jem'Hadar solider can be seen breathing. His chest is seen moving up and down. (00:30:35)

Broken Link - S4-E26

Revealing mistake: During the fight between Garak and Worf near the end of the episode, a Jefferies tube door is knocked out of its frame to reveal the end of the set - a dark room with a wooden scaffold and various other pieces of equipment (slow-mo helpful but not required). (00:36:00)