Stupidity: Considering he had a watch on in nearly every other episode, the Professor did not have his watch in this episode where they had a rescue deadline time (11:00) to be picked up along with the two Russians. Even if he forgot to put his watch on, he definitely would have paid attention to what time it was and got everyone to the location well before 11:00 to guarantee the rescue. Instead he relied on Gilligan to come up with the time which failed (an earlier submitted entry explains that part).
Smile, You're on Mars Camera - S2-E4
Stupidity: When the castaways stand in front of the camera waiting for it to operate, they hold signs up saying "SOS", "Help!", etc. thinking that will get them rescued. Even once the camera finally works and the gentlemen running the camera see them, this would do the castaways no good considering there is only picture (No sound) and the viewers think this is Mars. No location they were at were on the signs, and they can't be heard so the signs made were fully irrelevant for a rescue attempt.
Chosen answer: It looks like a mistake to me I see it when the Professor is put into a trance, but it is not there later.
Bowling255 ★