Reminds me of one of my internships. Was working on an oil price database and had to code a program to delete bad prices (it was more complicated that that, but that was the gist.)
Obviously I needed to test in test. I asked my fellow intern for the connection string to the test server... needless to say . I should have forseen the clueless girl would have given me prod.
At least the DBA was nice and had a backup >.>