Yeah it is confusing me because in all cases the camera was hidden. I just think the definitions they give should be clearcut. There may be a case for saying that the way that word functions "in real life" is a bit different than the textbook definition, in some cases.
Typically "candid" in photography means something like spontaneous and unposed (and therefore capturing something honest about the subject rather than unrehearsed). It doesn't imply that the camera is hidden, they just hid it in the TV show to make it easier to get those kinds of shots.
Candid does not mean "secretive and very guarded", though. People misunderstand the meaning of candid camera and assume it means "secret camera" and so use it that way, but that hasn't reached a level of misuse to redefine the meaning of candid.
