Shoddiest model you've ever seen approved by a senior person?

And what was wrong with it? I'm not just talking about IBD, either...could be a client's work, or if you work at a commercial bank or in the Treasury at a f500 feel free to contribute.

For example, I was reading 'Founders at Work' and came across their interview with Philip Greenspun of Arsdigita. He complained that the CEO "brought in his friend to be CFO. His buddy didn't have an accounting degree and he was really bad with numbers. He couldn't think with numbers, he couldn't do a spreadsheet model accurately." Everyone was relying on the CFO's spreadsheet, but Greenspun, who's an engineer, didn't think the numbers made sense and said the "assumptions were all wrong" (whether that means the operating assumptions section specifically I don't know).