He Pushed the Wrong Button!
Hey! It could happen to anyone...
From News of the Weird.com:
Raleigh, N.C.: The governor vetoed a pro-fracking bill, but pro-frackers worked to override it. However, governor's allies, led by Rep. Becky Carney, had the veto beat, by one vote--except that when it came time to actually vote, Carney pushed the wrong button, and the veto won. Carney: "Oh my gosh."
To see full story-ABC News (tip: The Atlantic)