Run a demo on live data? Sure! What could possibly go wrong? Hang on. Are you sure that's not working?
Until a puzzled accountant wandered in with a most confusing report. According to the printout he was reading, the company had quite suddenly accrued multiple billions of dollars for which there was no accounting.add-updateOf course these were the days before strict version control, so it was quite impossible for anyone to track down who the idiot responsible could have been.