The Code

Watching a new game show on BBC called The Code, in which contestants have to answer questions to win a guess at a number from a randomly generated 3 digit code.
The contestants were guessing the third and last digit of the code from a selection of three or four numbers.
"SEVEN!", bellows Tony.
They guess (not seven), and they guess wrong. They get the next question wrong, and they're out of the game.
Tony: "Shoulda gone seven."
Me: "But we don't know it was seven."
Tony: "No, coz last week I done it. I says five, stupid cow goes three, doesn't she!? And it was five!"