get this all the time at work. i truly enjoy playing dumb.
guest: uhhh...sir? i dropped my drink.
me: wiggly little critters, aren't they?
guest: can i get a replacement?
me: sure. that'll be $5.75.
guest: yeah, but i dropped it. it was almost full.
me: oh, no problem. i'll fix you right up. that'll be $5.75.
guest: (becoming indignant) you're going to charge me for another one?
me: look--if you buy a car and proceed to wrap it around a telephone pole, do you go back to the dealer and ask for another free car? perhaps you should consider drink insurance. it only costs an extra $5.75.
***
don't get me wrong--there are many situations where i will comp a replacement. if it was our fault, or if someone else knocked the drink out of the person's hand, then i have no problem replacing it. needless to say, good tippers always get a new drink. but there is a certain look about someone--a combination of nonverbal whining and insistence, that triggers the hardass response.