Ok...this needs to be said - Sorry, but i have to put in my two-cents

[Lord Magus]

They would let burgers sit in there for hours, and then serve them up.

That's a standard fixture at just about every BK.

Meat patties (burgers, chickens, fish) all have designated warmer-spaces (such as the steamer for burgers) where they're only suppossed to sit for 1/2 hour tops before being thrown out. Add to that that once an actuual SANDWICH is made, it's allowed to sit under the warmer light (where you always see the front crew pulling the food from) for 15 minutes, and by the time it gets to you it could LEGALLY be up to 45 minutes old..
and you start to wonder how old it could get when they don't care.. which is usually the case...