Revealing mistake: When he sits on the floor in front of Servalan, Jarrier's earring falls off. He fumbles at it briefly, and then the actor breaks character for just a moment, glancing nervously at the camera. When it's apparent there won't be a retake, he goes on with his lines.
Revealing mistake: Blake hands Cally a photo of Docholli, supposedly obtained from Zen. It's a publicity still of the actor that's not only in black & white (how low tech), but Cally has to hold her thumb rather conspicuously over the very 20th Century necktie he's wearing in the photo. You can see a bit of it anyway.