Visible crew/equipment: When the Ikarran tosses Sinclair into a pile of cargo crates, the commander's stunt double's face can be seen briefly. (00:33:05)
The Parliament of Dreams - S1-E6
Revealing mistake: As Lennier is first setting foot on the station, the same extra rides the escalator in the background up twice, even though we never saw him (nor was there time for him to) come down.
And the Sky Full of Stars - S1-E9
Revealing mistake: Inside Sinclair's mind, just after the knight shoots the fake Garibaldi, he lowers his gun and the end briefly lights up red. Evidently the actor accidentally pulled the trigger on the prop and triggered the light that lets the CGI team time the effects correctly. Note that it is not the gun barrel glowing after shooting, as it is not lit up before he lowers it.
Continuity mistake: When Garibaldi is saying goodbye to Lianna her hair keeps moving from behind her shoulders to hanging over her right front shoulder. (00:40:55 - 00:43:40)
Visible crew/equipment: Approximately 29 minutes and 10 seconds into this episode, right after Sinclair clasps hands with "The One", Garibaldi and Sinclair are on the ground. In the upper right corner of the shot there is a grip with a red baseball cap and red and white shirt on. He has long hair and spiffy glasses.
Chosen answer: She was promoted to Captain and thus had to leave Babylon 5, becoming a captain on a new Warlock class ship. Later on she retires/quits and becomes the top Ranger on Minbar.