Someone working on Excel, a product used inside government agencies and nearly every major business, including secret unapproved features? Yeah, that's absolutely a fire-able offense.
Didn't at least Excel 97 include a striped down version of Flight Simulator? You had to open an empty spreadsheet, fill in some value at some specific cell, voila, you're flying around. I'm sure that including that Easter egg was approved by Excel development's management, but unless they had a government and/or business specific version of Excel, it was there for everyone to play with. Did anyone at a government agency or business get fired for playing it?