My passive-aggressive response when faced with something like that was along the lines of "If it's so important that my butt be in the seat at 8 on the dot, then it's equally important that it be walking out the door at 5 on the dot."

Since at the time I was coding in a hallway-facing cube in a cubicle farm, after-hours was my best time to be able to get into "flow" and really get things accomplished without interruption.