For every rule, there are exceptions. Even something like the 5 second rule, which has saved many a spilled college student's dinner. Check it out:
I like to advocate a realistic approach to bacteria in the world around us; while it’s probably not the best idea to eat a pound of soil (for several reasons), contact with non-pristine surfaces doesn’t necessarily make food irreversibly spoiled. In fact, researchers have shown that food may be okay after being left as long as 30 seconds on a cafeteria floor.
There’s lots of places you wouldn’t want to eat food off the ground (hospitals, barnyards, and daycares come to mind) but its possible that we’ve become so accustomed to clean environments, and grown so afraid of all bacteria that we’ve lost perspective on the world around us. Not that long ago the closest thing to a table available was a tree stump or rock. And no one wiped those down with Lysol first.