I was on Jeopardy back in 1986. As you are all aware, the podiums contain small video screens on which players write their names and FJ answers.
During the commercial break between DJ and FJ, the contestant coordinators came out and walked the players through placing their wagers for FJ, which were written on the bottom half of the video screen. After writing your wager, the coordinator placed a small piece of hard plastic over the bottom half of the screen, covering the wager. (You're supposed to write your response on the top half of the screen, just above the plastic cover.)
Directly above the small video screen was a button. I asked one of the coordinators what the button did -- he told me that it erased all writing on the video screen.
I've always wondered what would happen if the player, not knowing the correct response to the FJ answer, were to hit the "erase" button.
Of course the staff has a record of the player's wager, and I don't suspect that they would disqualify the player since a full episode would have been taped by that point.
My FJ was a Great Lakes question, asking for 2 of the 5, but by process of elimination, I needed to select 2 out of 3.
I still missed it, but was far out of the running by that time, anyway.