Similar to the 5 second rule, when reaching down to pick up an item of food that you dropped on the ground within the 5 second rule but fumble and flip the piece of food over onto the other side as to contaminate it more, regardless of the 5 second rule it is dubbed uneatable.
man 1: what happened to the last cookie?
man 2: i threw it out
man 1 : why?
man 2 because i was gonna eat it but dropped it on the floor then flipped it over trying to pick it back up.
man 1: gotta be careful, the flip over rule strikes again.