I think I set something like this up once in a real tournament game, saw it and was like oh god this is embarrassing and then the guy didnt see it. Hehe, I tried to breath real deeply like I was really relieved so that he would eventually see it, because I knew it would throw him off his game -- dont remember how it went in the end, but it is still a funny use of gamesmanship. I have fallen for that a bit too, I think. Where you see that your opponent blundered and you missed it and then it nags your mind for the rest of the game so you lose. Hehe, blundering is always kind of funny.

Exactly the same mistake.