My apologies if this has mentioned this before, but the most shocking "Hey, I never noticed that before" moment was seeing the discarded newspaper lying on the floor in plain sight in the room behind and to the left of where McCoy is sitting at the end of "The Lights of Zetar". I mean, WTF!!How could that have not been noticed at the time of filming and, more importantly, edited out afterward!

Just how were they supposed to edit it out? The only way would have been to optically crop and enlarge the shot, making it grainier and cutting out Mr. Spock entirely. There was no digital editing in those days!