On a more hardware side, some of our older kit (semiconductor manufacturing machines) shipped with their bright red EMO mushroom buttons entirely exposed, as it was mandatory for CE marking (being able to whack them from any angle).
Of course this lead to the inevitable misoperation, from being smacked by various operator body parts (the front panel buttons were at roughly arse level for example, and the ones at the rear usually around chest height).
Needless to say the first thing most of our customers did after the tools were installed (sometimes before they were even powered on) was glue perspex collars around all the buttons to try and prevent this.
Forget lost program runs, try losing 150 wafers worth of chips-in-production. Not cheap...