When I eat at Doolittles and find a bug in my food, show my server who says he's sorry, watch the server show the manager the bug, receive no table visit from the manager, and then subsequently get charged for the bugged dish, I give Doolittles a one-star review.
The Doolittles staff had all the opportunity to remedy a problem but decided not to.
This is the shortest Yelp review I've ever written, but there's really no need to elaborate.