In bridge, there are some times when you can assure yourself of x number of tricks (just enough for your contract) by making a safety play to guard against an adverse 4-1 distribution. If you don't make the safety play, and instead lead out three top cards, you will make an overtrick if the suit breaks 3-2, and go down one if it breaks 4-1 (because you can't get back to dummy to take the fifth trick. Most rubber players would make the safety play to maximize expected points, and most duplicate players would take the three tops to maximize expected tricks.
Suppose you are a member of a "traveling" duplicate pair. As you approach a certain table, you notice declarers looking glum as they leave the table. From this, you infer that one or more declarers caught a bad break. Sure enough, when you sit down and declare, you see the road fork between making a safety play and laying down three top cards.
Now it's unethical to peek at the score sheet to find out whether others made an overtrick, their contract, or down one. But is it unethical to make the safety play based on the body language of the two preceding declarers?
Suppose someone else was the only declarer to make the safety play. The tournament director observes this and accuses him of cheating. He defends himself by saying that he was dissatisfied with his position in the standings, was in a "top or bottom" mode, and earned a top on this one hand. How would these claims be resolved?