A sleepy bank employee dozed off briefly with his finger on the number 2 key of his computer, and by the time he woke up he had transferred 222,222,222 Euros ($293 million) to a person's account instead of the 42 Euros ($80) that was supposed to be transferred.

The employee didn't immediately notice the mistake and neither did a supervisor. The bonanza was transferred by a German bank on April 2, 2012.

The colossal bank screw-up came to light this week when a Hessian State Court ruled the drowsy employee's supervisor had been wrongly fired for not catching the error.

The court documents obtained by ABC News do not identify the bank or the employees, other than to say the supervisor had been a loyal employee for 27 years. The court concluded the bank's verification system failed, not the supervisor. The error was quickly noticed, however, by the bank's back-up system which did catch the error.