Let's say a player has two loyalty cards: one final five card: "examining player is executed" and one "You are a cylon card". Another player is examining both cards (using Baltar's ability or a quorum card). He immediately reveals the final five card and is executed, but he has seen the other card. Can he talk about it (probably after drawing the new loyalty card himself) or, since he is dead, he has to take the secret to the grave?
Well, the player is still in the game, so the usual secrecy rules about hidden cards should apply. In other words, say generic things that may or may not be true. So accusing the other player of being a cylon would be acceptable, I presume.
ps. Welcome to bgg.
Agreed. Keep to the confines of secrecy rules regarding loyalty cards. However, if you're coming back as another (human) character, I wouldn't spill the details of what you saw until you see what your new Loyalty card is
Also, this isn't like Werewolf where dead players are forbidden to communicate with the remaining, living players. It's not THAT thematic where dead people can't talk. AFAIK, you're free to talk strategy and your insights with others even if you're eliminated via IN.